diff --git a/Devices/btt-panda-touch/Source/devices/Display.cpp b/Devices/btt-panda-touch/Source/devices/Display.cpp
index 7da8e901..24607968 100644
--- a/Devices/btt-panda-touch/Source/devices/Display.cpp
+++ b/Devices/btt-panda-touch/Source/devices/Display.cpp
@@ -4,7 +4,7 @@
 #include <PwmBacklight.h>
 #include <RgbDisplay.h>
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable createTouch() {
+std::shared_ptr<tt::hal::touch::TouchDevice> createTouch() {
     // Note for future changes: Reset pin is 41 and interrupt pin is 40
     auto configuration = std::make_unique<Gt911Touch::Configuration>(
         I2C_NUM_0,
diff --git a/Devices/cyd-4848s040c/Source/devices/St7701Display.cpp b/Devices/cyd-4848s040c/Source/devices/St7701Display.cpp
index bc337e4e..e9c14889 100644
--- a/Devices/cyd-4848s040c/Source/devices/St7701Display.cpp
+++ b/Devices/cyd-4848s040c/Source/devices/St7701Display.cpp
@@ -219,7 +219,7 @@ lvgl_port_display_rgb_cfg_t St7701Display::getLvglPortDisplayRgbConfig(esp_lcd_p
     };
 }
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable St7701Display::getTouchDevice() {
+std::shared_ptr<tt::hal::touch::TouchDevice> St7701Display::getTouchDevice() {
     if (touchDevice == nullptr) {
         auto configuration = std::make_unique<Gt911Touch::Configuration>(
            I2C_NUM_0,
diff --git a/Devices/cyd-4848s040c/Source/devices/St7701Display.h b/Devices/cyd-4848s040c/Source/devices/St7701Display.h
index 2ae12c4f..49efa45e 100644
--- a/Devices/cyd-4848s040c/Source/devices/St7701Display.h
+++ b/Devices/cyd-4848s040c/Source/devices/St7701Display.h
@@ -7,7 +7,7 @@
 
 class St7701Display final : public EspLcdDisplay {
 
-    std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable touchDevice;
+    std::shared_ptr<tt::hal::touch::TouchDevice> touchDevice;
 
     bool createIoHandle(esp_lcd_panel_io_handle_t& outHandle) override;
 
@@ -27,7 +27,7 @@ public:
 
     std::string getDescription() const override { return "ST7701S RGB display"; }
 
-    std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable getTouchDevice() override;
+    std::shared_ptr<tt::hal::touch::TouchDevice> getTouchDevice() override;
 
     void setBacklightDuty(uint8_t backlightDuty) override;
 
diff --git a/Devices/cyd-8048s043c/Source/devices/Display.cpp b/Devices/cyd-8048s043c/Source/devices/Display.cpp
index 65a2c522..2d1e61e2 100644
--- a/Devices/cyd-8048s043c/Source/devices/Display.cpp
+++ b/Devices/cyd-8048s043c/Source/devices/Display.cpp
@@ -4,7 +4,7 @@
 #include <PwmBacklight.h>
 #include <RgbDisplay.h>
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable createTouch() {
+std::shared_ptr<tt::hal::touch::TouchDevice> createTouch() {
     // Note for future changes: Reset pin is 38 and interrupt pin is 18
     // or INT = NC, schematic and other info floating around is kinda conflicting...
     auto configuration = std::make_unique<Gt911Touch::Configuration>(
diff --git a/Devices/elecrow-crowpanel-advance-50/Source/devices/Display.cpp b/Devices/elecrow-crowpanel-advance-50/Source/devices/Display.cpp
index 9440b3d9..3476d82d 100644
--- a/Devices/elecrow-crowpanel-advance-50/Source/devices/Display.cpp
+++ b/Devices/elecrow-crowpanel-advance-50/Source/devices/Display.cpp
@@ -3,7 +3,7 @@
 #include <Gt911Touch.h>
 #include <RgbDisplay.h>
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable createTouch() {
+std::shared_ptr<tt::hal::touch::TouchDevice> createTouch() {
     // Note for future changes: Reset pin is 38 and interrupt pin is 18
     // or INT = NC, schematic and other info floating around is kinda conflicting...
     auto configuration = std::make_unique<Gt911Touch::Configuration>(
diff --git a/Devices/elecrow-crowpanel-basic-50/Source/devices/Display.cpp b/Devices/elecrow-crowpanel-basic-50/Source/devices/Display.cpp
index 72771a1a..6a9f70e7 100644
--- a/Devices/elecrow-crowpanel-basic-50/Source/devices/Display.cpp
+++ b/Devices/elecrow-crowpanel-basic-50/Source/devices/Display.cpp
@@ -4,7 +4,7 @@
 #include <PwmBacklight.h>
 #include <RgbDisplay.h>
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable createTouch() {
+std::shared_ptr<tt::hal::touch::TouchDevice> createTouch() {
     // Note for future changes: Reset pin is 38 and interrupt pin is 18
     // or INT = NC, schematic and other info floating around is kinda conflicting...
     auto configuration = std::make_unique<Gt911Touch::Configuration>(
diff --git a/Devices/guition-jc3248w535c/Source/Axs15231b/Axs15231bDisplay.h b/Devices/guition-jc3248w535c/Source/Axs15231b/Axs15231bDisplay.h
index 4c9e39b3..1f8a53df 100644
--- a/Devices/guition-jc3248w535c/Source/Axs15231b/Axs15231bDisplay.h
+++ b/Devices/guition-jc3248w535c/Source/Axs15231b/Axs15231bDisplay.h
@@ -72,23 +72,23 @@ public:
         uint32_t bufferSize; // Size in pixel count. 0 means default, which is 1/10 of the screen size
         lcd_rgb_element_order_t rgbElementOrder;
         std::shared_ptr<tt::hal::touch::TouchDevice> touch;
-        std::function<void(uint8_t)> _Nullable backlightDutyFunction = nullptr;
+        std::function<void(uint8_t)> backlightDutyFunction = nullptr;
     };
 
 private:
 
-    esp_lcd_panel_io_handle_t _Nullable ioHandle = nullptr;
-    esp_lcd_panel_handle_t _Nullable panelHandle = nullptr;
-    lv_display_t* _Nullable lvglDisplay = nullptr;
-    uint16_t* _Nullable buffer1 = nullptr;
-    uint16_t* _Nullable buffer2 = nullptr;
-    uint16_t* _Nullable tempBuf = nullptr;
-    SemaphoreHandle_t _Nullable teSyncSemaphore = nullptr;
+    esp_lcd_panel_io_handle_t ioHandle = nullptr;
+    esp_lcd_panel_handle_t panelHandle = nullptr;
+    lv_display_t* lvglDisplay = nullptr;
+    uint16_t* buffer1 = nullptr;
+    uint16_t* buffer2 = nullptr;
+    uint16_t* tempBuf = nullptr;
+    SemaphoreHandle_t teSyncSemaphore = nullptr;
     bool teIsrInstalled = false;
     bool isrServiceInstalledByUs = false;
 
     std::unique_ptr<Configuration> configuration;
-    std::shared_ptr<tt::hal::display::DisplayDriver> _Nullable displayDriver;
+    std::shared_ptr<tt::hal::display::DisplayDriver> displayDriver;
 
     bool createIoHandle();
 
@@ -118,9 +118,9 @@ public:
 
     bool stopLvgl() override;
 
-    lv_display_t* _Nullable getLvglDisplay() const override { return lvglDisplay; }
+    lv_display_t* getLvglDisplay() const override { return lvglDisplay; }
 
-    std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable getTouchDevice() override { return configuration->touch; }
+    std::shared_ptr<tt::hal::touch::TouchDevice> getTouchDevice() override { return configuration->touch; }
 
     void setBacklightDuty(uint8_t backlightDuty) override {
         if (configuration->backlightDutyFunction != nullptr) {
@@ -132,7 +132,7 @@ public:
 
     bool supportsDisplayDriver() const override { return true; }
 
-    std::shared_ptr<tt::hal::display::DisplayDriver> _Nullable getDisplayDriver() override;
+    std::shared_ptr<tt::hal::display::DisplayDriver> getDisplayDriver() override;
 
     static void lvgl_port_flush_callback(lv_display_t *drv, const lv_area_t *area, uint8_t *color_map);
 
diff --git a/Devices/guition-jc8048w550c/Source/devices/Display.cpp b/Devices/guition-jc8048w550c/Source/devices/Display.cpp
index 65a2c522..2d1e61e2 100644
--- a/Devices/guition-jc8048w550c/Source/devices/Display.cpp
+++ b/Devices/guition-jc8048w550c/Source/devices/Display.cpp
@@ -4,7 +4,7 @@
 #include <PwmBacklight.h>
 #include <RgbDisplay.h>
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable createTouch() {
+std::shared_ptr<tt::hal::touch::TouchDevice> createTouch() {
     // Note for future changes: Reset pin is 38 and interrupt pin is 18
     // or INT = NC, schematic and other info floating around is kinda conflicting...
     auto configuration = std::make_unique<Gt911Touch::Configuration>(
diff --git a/Devices/lilygo-tdeck/Source/devices/TdeckKeyboard.h b/Devices/lilygo-tdeck/Source/devices/TdeckKeyboard.h
index c79b54dd..7204f1a0 100644
--- a/Devices/lilygo-tdeck/Source/devices/TdeckKeyboard.h
+++ b/Devices/lilygo-tdeck/Source/devices/TdeckKeyboard.h
@@ -5,7 +5,7 @@
 
 class TdeckKeyboard final : public tt::hal::keyboard::KeyboardDevice {
 
-    lv_indev_t* _Nullable deviceHandle = nullptr;
+    lv_indev_t* deviceHandle = nullptr;
 
 public:
 
@@ -15,5 +15,5 @@ public:
     bool startLvgl(lv_display_t* display) override;
     bool stopLvgl() override;
     bool isAttached() const override;
-    lv_indev_t* _Nullable getLvglIndev() override { return deviceHandle; }
+    lv_indev_t* getLvglIndev() override { return deviceHandle; }
 };
diff --git a/Devices/lilygo-tlora-pager/Source/devices/TpagerEncoder.h b/Devices/lilygo-tlora-pager/Source/devices/TpagerEncoder.h
index 026d1cb9..85948470 100644
--- a/Devices/lilygo-tlora-pager/Source/devices/TpagerEncoder.h
+++ b/Devices/lilygo-tlora-pager/Source/devices/TpagerEncoder.h
@@ -5,7 +5,7 @@
 
 class TpagerEncoder final : public tt::hal::encoder::EncoderDevice {
 
-    lv_indev_t* _Nullable encHandle = nullptr;
+    lv_indev_t* encHandle = nullptr;
     pcnt_unit_handle_t encPcntUnit = nullptr;
 
     bool initEncoder();
@@ -26,5 +26,5 @@ public:
 
     int getEncoderPulses() const;
 
-    lv_indev_t* _Nullable getLvglIndev() override { return encHandle; }
+    lv_indev_t* getLvglIndev() override { return encHandle; }
 };
diff --git a/Devices/lilygo-tlora-pager/Source/devices/TpagerKeyboard.h b/Devices/lilygo-tlora-pager/Source/devices/TpagerKeyboard.h
index 857206ff..f8a40e5e 100644
--- a/Devices/lilygo-tlora-pager/Source/devices/TpagerKeyboard.h
+++ b/Devices/lilygo-tlora-pager/Source/devices/TpagerKeyboard.h
@@ -10,7 +10,7 @@
 
 class TpagerKeyboard final : public tt::hal::keyboard::KeyboardDevice {
 
-    lv_indev_t* _Nullable kbHandle = nullptr;
+    lv_indev_t* kbHandle = nullptr;
     gpio_num_t backlightPin = GPIO_NUM_NC;
     ledc_timer_t backlightTimer;
     ledc_channel_t backlightChannel;
@@ -45,7 +45,7 @@ public:
     bool stopLvgl() override;
 
     bool isAttached() const override;
-    lv_indev_t* _Nullable getLvglIndev() override { return kbHandle; }
+    lv_indev_t* getLvglIndev() override { return kbHandle; }
 
     bool setBacklightDuty(uint8_t duty);
     void makeBacklightImpulse();
diff --git a/Devices/m5stack-cardputer-adv/Source/devices/CardputerKeyboard.h b/Devices/m5stack-cardputer-adv/Source/devices/CardputerKeyboard.h
index fecafc09..89f95ba9 100644
--- a/Devices/m5stack-cardputer-adv/Source/devices/CardputerKeyboard.h
+++ b/Devices/m5stack-cardputer-adv/Source/devices/CardputerKeyboard.h
@@ -9,7 +9,7 @@
 
 class CardputerKeyboard final : public tt::hal::keyboard::KeyboardDevice {
 
-    lv_indev_t* _Nullable kbHandle = nullptr;
+    lv_indev_t* kbHandle = nullptr;
     QueueHandle_t queue = nullptr;
 
     std::shared_ptr<Tca8418> keypad;
@@ -42,5 +42,5 @@ public:
     bool stopLvgl() override;
 
     bool isAttached() const override;
-    lv_indev_t* _Nullable getLvglIndev() override { return kbHandle; }
+    lv_indev_t* getLvglIndev() override { return kbHandle; }
 };
diff --git a/Devices/m5stack-cardputer/Source/devices/CardputerEncoder.h b/Devices/m5stack-cardputer/Source/devices/CardputerEncoder.h
index f97ca7cf..0deea817 100644
--- a/Devices/m5stack-cardputer/Source/devices/CardputerEncoder.h
+++ b/Devices/m5stack-cardputer/Source/devices/CardputerEncoder.h
@@ -13,7 +13,7 @@
 class CardputerEncoder final : public tt::hal::encoder::EncoderDevice {
     KEYBOARD::Keyboard keyboard;
     int lastKeyNum = 0;
-    lv_indev_t* _Nullable lvglDevice = nullptr;
+    lv_indev_t* lvglDevice = nullptr;
 
     static void readCallback(lv_indev_t* indev, lv_indev_data_t* data);
 
@@ -25,5 +25,5 @@ public:
     bool startLvgl(lv_display_t* display) override;
     bool stopLvgl() override;
 
-    lv_indev_t* _Nullable getLvglIndev() override { return lvglDevice; }
+    lv_indev_t* getLvglIndev() override { return lvglDevice; }
 };
diff --git a/Devices/m5stack-cardputer/Source/devices/CardputerKeyboard.h b/Devices/m5stack-cardputer/Source/devices/CardputerKeyboard.h
index f57dff06..4501ffbd 100644
--- a/Devices/m5stack-cardputer/Source/devices/CardputerKeyboard.h
+++ b/Devices/m5stack-cardputer/Source/devices/CardputerKeyboard.h
@@ -8,7 +8,7 @@
 class CardputerKeyboard : public tt::hal::keyboard::KeyboardDevice {
     KEYBOARD::Keyboard keyboard;
     int lastKeyNum = 0;
-    lv_indev_t* _Nullable lvglDevice = nullptr;
+    lv_indev_t* lvglDevice = nullptr;
 
     static void readCallback(lv_indev_t* indev, lv_indev_data_t* data);
 
@@ -22,5 +22,5 @@ public:
 
     bool isAttached() const override { return true; }
 
-    lv_indev_t* _Nullable getLvglIndev() override { return lvglDevice; }
+    lv_indev_t* getLvglIndev() override { return lvglDevice; }
 };
diff --git a/Devices/simulator/CMakeLists.txt b/Devices/simulator/CMakeLists.txt
index 7750f97a..6e0dc4a3 100644
--- a/Devices/simulator/CMakeLists.txt
+++ b/Devices/simulator/CMakeLists.txt
@@ -21,7 +21,4 @@ if (NOT DEFINED ENV{ESP_IDF_VERSION})
 
     target_link_libraries(Simulator PRIVATE ${SDL2_LIBRARIES})
 
-    add_definitions(-D_Nullable=)
-    add_definitions(-D_Nonnull=)
-
 endif()
diff --git a/Devices/simulator/Source/hal/SdlDisplay.h b/Devices/simulator/Source/hal/SdlDisplay.h
index fca3cb24..554db47b 100644
--- a/Devices/simulator/Source/hal/SdlDisplay.h
+++ b/Devices/simulator/Source/hal/SdlDisplay.h
@@ -20,10 +20,10 @@ public:
     bool supportsLvgl() const override { return true; }
     bool startLvgl() override { return displayHandle != nullptr; }
     bool stopLvgl() override { check(false, "Not supported"); }
-    lv_display_t* _Nullable getLvglDisplay() const override { return displayHandle; }
+    lv_display_t* getLvglDisplay() const override { return displayHandle; }
 
-    std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable getTouchDevice() override { return std::make_shared<SdlTouch>(); }
+    std::shared_ptr<tt::hal::touch::TouchDevice> getTouchDevice() override { return std::make_shared<SdlTouch>(); }
 
     bool supportsDisplayDriver() const override { return false; }
-    std::shared_ptr<tt::hal::display::DisplayDriver> _Nullable getDisplayDriver() override { return nullptr; }
+    std::shared_ptr<tt::hal::display::DisplayDriver> getDisplayDriver() override { return nullptr; }
 };
diff --git a/Devices/simulator/Source/hal/SdlKeyboard.h b/Devices/simulator/Source/hal/SdlKeyboard.h
index 6fc1513e..876bf70d 100644
--- a/Devices/simulator/Source/hal/SdlKeyboard.h
+++ b/Devices/simulator/Source/hal/SdlKeyboard.h
@@ -6,7 +6,7 @@
 
 class SdlKeyboard final : public tt::hal::keyboard::KeyboardDevice {
 
-    lv_indev_t* _Nullable handle = nullptr;
+    lv_indev_t* handle = nullptr;
 
 public:
 
@@ -22,5 +22,5 @@ public:
 
     bool isAttached() const override { return true; }
 
-    lv_indev_t* _Nullable getLvglIndev() override { return handle; }
+    lv_indev_t* getLvglIndev() override { return handle; }
 };
diff --git a/Devices/simulator/Source/hal/SdlTouch.h b/Devices/simulator/Source/hal/SdlTouch.h
index 0c3bead6..09ebc757 100644
--- a/Devices/simulator/Source/hal/SdlTouch.h
+++ b/Devices/simulator/Source/hal/SdlTouch.h
@@ -6,7 +6,7 @@
 
 class SdlTouch final : public tt::hal::touch::TouchDevice {
 
-    lv_indev_t* _Nullable handle = nullptr;
+    lv_indev_t* handle = nullptr;
 
 public:
 
@@ -27,10 +27,10 @@ public:
 
     bool stopLvgl() override { check(false, "Not supported"); }
 
-    lv_indev_t* _Nullable getLvglIndev() override { return handle; }
+    lv_indev_t* getLvglIndev() override { return handle; }
 
     bool supportsTouchDriver() override { return false; }
 
-    std::shared_ptr<tt::hal::touch::TouchDriver> _Nullable getTouchDriver() override { return nullptr; };
+    std::shared_ptr<tt::hal::touch::TouchDriver> getTouchDriver() override { return nullptr; };
 };
 
diff --git a/Devices/unphone/Source/devices/Hx8357Display.cpp b/Devices/unphone/Source/devices/Hx8357Display.cpp
index 3bd0f0ff..80a2f7f6 100644
--- a/Devices/unphone/Source/devices/Hx8357Display.cpp
+++ b/Devices/unphone/Source/devices/Hx8357Display.cpp
@@ -99,7 +99,7 @@ bool Hx8357Display::stopLvgl() {
     return true;
 }
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable Hx8357Display::getTouchDevice() {
+std::shared_ptr<tt::hal::touch::TouchDevice> Hx8357Display::getTouchDevice() {
     if (touchDevice == nullptr) {
         touchDevice = std::reinterpret_pointer_cast<tt::hal::touch::TouchDevice>(createTouch());
         LOGGER.info("Created touch device");
diff --git a/Devices/unphone/Source/devices/Hx8357Display.h b/Devices/unphone/Source/devices/Hx8357Display.h
index e081a452..3414d2be 100644
--- a/Devices/unphone/Source/devices/Hx8357Display.h
+++ b/Devices/unphone/Source/devices/Hx8357Display.h
@@ -21,10 +21,10 @@
 
 class Hx8357Display : public tt::hal::display::DisplayDevice {
 
-    uint8_t* _Nullable buffer = nullptr;
-    lv_display_t* _Nullable lvglDisplay = nullptr;
-    std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable touchDevice;
-    std::shared_ptr<tt::hal::display::DisplayDriver> _Nullable nativeDisplay;
+    uint8_t* buffer = nullptr;
+    lv_display_t* lvglDisplay = nullptr;
+    std::shared_ptr<tt::hal::touch::TouchDevice> touchDevice;
+    std::shared_ptr<tt::hal::display::DisplayDriver> nativeDisplay;
 
     class Hx8357Driver : public tt::hal::display::DisplayDriver {
         std::shared_ptr<tt::Lock> lock = tt::hal::spi::getLock(SPI2_HOST);
@@ -51,14 +51,14 @@ public:
 
     bool stopLvgl() override;
 
-    std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable getTouchDevice() override;
+    std::shared_ptr<tt::hal::touch::TouchDevice> getTouchDevice() override;
 
-    lv_display_t* _Nullable getLvglDisplay() const override { return lvglDisplay; }
+    lv_display_t* getLvglDisplay() const override { return lvglDisplay; }
 
     // TODO: Set to true after fixing UnPhoneDisplayDriver
     bool supportsDisplayDriver() const override { return false; }
 
-    std::shared_ptr<tt::hal::display::DisplayDriver> _Nullable getDisplayDriver() override {
+    std::shared_ptr<tt::hal::display::DisplayDriver> getDisplayDriver() override {
         if (nativeDisplay == nullptr) {
             nativeDisplay = std::make_shared<Hx8357Driver>();
         }
diff --git a/Devices/waveshare-s3-touch-lcd-128/Source/devices/Display.cpp b/Devices/waveshare-s3-touch-lcd-128/Source/devices/Display.cpp
index ca1e0e4a..f152d94f 100644
--- a/Devices/waveshare-s3-touch-lcd-128/Source/devices/Display.cpp
+++ b/Devices/waveshare-s3-touch-lcd-128/Source/devices/Display.cpp
@@ -4,7 +4,7 @@
 #include <PwmBacklight.h>
 #include <Gc9a01Display.h>
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable createTouch() {
+std::shared_ptr<tt::hal::touch::TouchDevice> createTouch() {
     auto configuration = std::make_unique<Cst816sTouch::Configuration>(
         I2C_NUM_0,
         240,
diff --git a/Devices/waveshare-s3-touch-lcd-147/Source/devices/Jd9853Display.h b/Devices/waveshare-s3-touch-lcd-147/Source/devices/Jd9853Display.h
index b84754e2..fd06223b 100644
--- a/Devices/waveshare-s3-touch-lcd-147/Source/devices/Jd9853Display.h
+++ b/Devices/waveshare-s3-touch-lcd-147/Source/devices/Jd9853Display.h
@@ -67,7 +67,7 @@ public:
         uint32_t bufferSize; // Size in pixel count. 0 means default, which is 1/10 of the screen size
         lcd_rgb_element_order_t rgbElementOrder;
         std::shared_ptr<tt::hal::touch::TouchDevice> touch;
-        std::function<void(uint8_t)> _Nullable backlightDutyFunction = nullptr;
+        std::function<void(uint8_t)> backlightDutyFunction = nullptr;
     };
 
 private:
@@ -93,7 +93,7 @@ public:
 
     std::string getDescription() const override { return "JD9853 display"; }
 
-    std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable getTouchDevice() override { return configuration->touch; }
+    std::shared_ptr<tt::hal::touch::TouchDevice> getTouchDevice() override { return configuration->touch; }
 
     void setBacklightDuty(uint8_t backlightDuty) override {
         if (configuration->backlightDutyFunction != nullptr) {
diff --git a/Devices/waveshare-s3-touch-lcd-43/Source/devices/Display.cpp b/Devices/waveshare-s3-touch-lcd-43/Source/devices/Display.cpp
index 85ff2ede..49aba831 100644
--- a/Devices/waveshare-s3-touch-lcd-43/Source/devices/Display.cpp
+++ b/Devices/waveshare-s3-touch-lcd-43/Source/devices/Display.cpp
@@ -3,7 +3,7 @@
 #include <Gt911Touch.h>
 #include <RgbDisplay.h>
 
-std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable createTouch() {
+std::shared_ptr<tt::hal::touch::TouchDevice> createTouch() {
     // Note for future changes: Reset pin is 38 and interrupt pin is 18
     // or INT = NC, schematic and other info floating around is kinda conflicting...
     auto configuration = std::make_unique<Gt911Touch::Configuration>(
diff --git a/Drivers/ButtonControl/Source/ButtonControl.h b/Drivers/ButtonControl/Source/ButtonControl.h
index 74886ce6..14683090 100644
--- a/Drivers/ButtonControl/Source/ButtonControl.h
+++ b/Drivers/ButtonControl/Source/ButtonControl.h
@@ -37,7 +37,7 @@ private:
         bool triggerLongPress = false;
     };
 
-    lv_indev_t* _Nullable deviceHandle = nullptr;
+    lv_indev_t* deviceHandle = nullptr;
     std::shared_ptr<tt::Thread> driverThread;
     bool interruptDriverThread = false;
     tt::Mutex mutex;
@@ -67,7 +67,8 @@ public:
     bool startLvgl(lv_display_t* display) override;
     bool stopLvgl() override;
 
-    lv_indev_t* _Nullable getLvglIndev() override { return deviceHandle; }
+    /** Could return nullptr if not started */
+    lv_indev_t* getLvglIndev() override { return deviceHandle; }
 
     static std::shared_ptr<ButtonControl> createOneButtonControl(tt::hal::gpio::Pin pin) {
         return std::make_shared<ButtonControl>(std::vector {
diff --git a/Drivers/CST816S/Source/Cst816Touch.h b/Drivers/CST816S/Source/Cst816Touch.h
index a926c347..67a0f1a0 100644
--- a/Drivers/CST816S/Source/Cst816Touch.h
+++ b/Drivers/CST816S/Source/Cst816Touch.h
@@ -49,7 +49,7 @@ private:
     std::unique_ptr<Configuration> configuration;
     esp_lcd_panel_io_handle_t ioHandle = nullptr;
     esp_lcd_touch_handle_t touchHandle = nullptr;
-    lv_indev_t* _Nullable deviceHandle = nullptr;
+    lv_indev_t* deviceHandle = nullptr;
 
     void cleanup();
 
diff --git a/Drivers/EspLcdCompat/Source/EspLcdDisplay.h b/Drivers/EspLcdCompat/Source/EspLcdDisplay.h
index d9ae558d..2819acd0 100644
--- a/Drivers/EspLcdCompat/Source/EspLcdDisplay.h
+++ b/Drivers/EspLcdCompat/Source/EspLcdDisplay.h
@@ -10,10 +10,10 @@
 /** @deprecated use EspLcdDisplayV2 */
 class EspLcdDisplay : public tt::hal::display::DisplayDevice {
 
-    esp_lcd_panel_io_handle_t _Nullable ioHandle = nullptr;
-    esp_lcd_panel_handle_t _Nullable panelHandle = nullptr;
-    lv_display_t* _Nullable lvglDisplay = nullptr;
-    std::shared_ptr<tt::hal::display::DisplayDriver> _Nullable displayDriver;
+    esp_lcd_panel_io_handle_t ioHandle = nullptr;
+    esp_lcd_panel_handle_t panelHandle = nullptr;
+    lv_display_t* lvglDisplay = nullptr;
+    std::shared_ptr<tt::hal::display::DisplayDriver> displayDriver;
     std::shared_ptr<tt::Lock> lock;
     lcd_rgb_element_order_t rgbElementOrder;
 
@@ -52,7 +52,7 @@ public:
 
     bool stopLvgl() final;
 
-    lv_display_t* _Nullable getLvglDisplay() const final { return lvglDisplay; }
+    lv_display_t* getLvglDisplay() const final { return lvglDisplay; }
 
     // endregion
 
@@ -61,7 +61,7 @@ public:
     bool supportsDisplayDriver() const override { return true; }
 
     /** @return a NativeDisplay instance if this device supports it */
-    std::shared_ptr<tt::hal::display::DisplayDriver> _Nullable getDisplayDriver() final;
+    std::shared_ptr<tt::hal::display::DisplayDriver> getDisplayDriver() final;
 
     // endregion
 };
diff --git a/Drivers/EspLcdCompat/Source/EspLcdTouch.h b/Drivers/EspLcdCompat/Source/EspLcdTouch.h
index 035c6483..3e7056b7 100644
--- a/Drivers/EspLcdCompat/Source/EspLcdTouch.h
+++ b/Drivers/EspLcdCompat/Source/EspLcdTouch.h
@@ -11,7 +11,7 @@ class EspLcdTouch : public tt::hal::touch::TouchDevice {
     esp_lcd_touch_config_t config;
     esp_lcd_panel_io_handle_t _Nullable ioHandle = nullptr;
     esp_lcd_touch_handle_t _Nullable touchHandle = nullptr;
-    lv_indev_t* _Nullable lvglDevice = nullptr;
+    lv_indev_t* lvglDevice = nullptr;
     std::shared_ptr<tt::hal::touch::TouchDriver> touchDriver;
 
 protected:
@@ -36,7 +36,7 @@ public:
 
     bool stopLvgl() final;
 
-    lv_indev_t* _Nullable getLvglIndev() final { return lvglDevice; }
+    lv_indev_t* getLvglIndev() final { return lvglDevice; }
 
     bool supportsTouchDriver() override { return true; }
 
diff --git a/Drivers/FT6x36/Source/Ft6x36Touch.h b/Drivers/FT6x36/Source/Ft6x36Touch.h
index e7328a30..bbeb9023 100644
--- a/Drivers/FT6x36/Source/Ft6x36Touch.h
+++ b/Drivers/FT6x36/Source/Ft6x36Touch.h
@@ -34,7 +34,7 @@ public:
 private:
 
     std::unique_ptr<Configuration> configuration;
-    lv_indev_t* _Nullable deviceHandle = nullptr;
+    lv_indev_t* deviceHandle = nullptr;
     FT6X36 driver = FT6X36(configuration->port, configuration->pinInterrupt);
     std::shared_ptr<tt::Thread> driverThread;
     bool interruptDriverThread = false;
@@ -65,7 +65,7 @@ public:
     bool startLvgl(lv_display_t* display) override;
     bool stopLvgl() override;
 
-    lv_indev_t* _Nullable getLvglIndev() override { return deviceHandle; }
+    lv_indev_t* getLvglIndev() override { return deviceHandle; }
 
     class Ft6TouchDriver : public tt::hal::touch::TouchDriver {
     public:
diff --git a/Drivers/ILI934x/Source/Ili934xDisplay.h b/Drivers/ILI934x/Source/Ili934xDisplay.h
index d44bde8c..9337e5f6 100644
--- a/Drivers/ILI934x/Source/Ili934xDisplay.h
+++ b/Drivers/ILI934x/Source/Ili934xDisplay.h
@@ -25,7 +25,7 @@ public:
         bool swapBytes;
         uint32_t bufferSize; // Pixel count, not byte count. Set to 0 for default (1/10th of display size)
         std::shared_ptr<tt::hal::touch::TouchDevice> touch;
-        std::function<void(uint8_t)> _Nullable backlightDutyFunction;
+        std::function<void(uint8_t)> backlightDutyFunction; // Nullable
         gpio_num_t resetPin;
         lcd_rgb_element_order_t rgbElementOrder;
     };
diff --git a/Firmware/CMakeLists.txt b/Firmware/CMakeLists.txt
index 1f06ab3d..85d632d7 100644
--- a/Firmware/CMakeLists.txt
+++ b/Firmware/CMakeLists.txt
@@ -43,8 +43,6 @@ else ()
         SDL2::SDL2-static SDL2-static
     )
 
-    add_definitions(-D_Nullable=)
-    add_definitions(-D_Nonnull=)
 endif ()
 
 add_custom_target(AlwaysRun
diff --git a/Modules/hal-device-module/CMakeLists.txt b/Modules/hal-device-module/CMakeLists.txt
index b8bc2cf4..0ccdb119 100644
--- a/Modules/hal-device-module/CMakeLists.txt
+++ b/Modules/hal-device-module/CMakeLists.txt
@@ -30,9 +30,6 @@ else ()
         PUBLIC Include/
     )
 
-    add_definitions(-D_Nullable=)
-    add_definitions(-D_Nonnull=)
-
     target_link_libraries(hal-device-module PUBLIC
         TactilityFreeRtos
         TactilityCore
diff --git a/Modules/hal-device-module/Include/tactility/hal/Device.h b/Modules/hal-device-module/Include/tactility/hal/Device.h
index d25dfa23..db7e68a6 100644
--- a/Modules/hal-device-module/Include/tactility/hal/Device.h
+++ b/Modules/hal-device-module/Include/tactility/hal/Device.h
@@ -79,17 +79,17 @@ void registerDevice(const std::shared_ptr<Device>& device);
 /** Remove a device from the registry. */
 void deregisterDevice(const std::shared_ptr<Device>& device);
 
-/** Find a single device with a custom filter */
-std::shared_ptr<Device> _Nullable findDevice(const std::function<bool(const std::shared_ptr<Device>&)>& filterFunction);
+/** Find a single device with a custom filter. Could return nullptr if not found. */
+std::shared_ptr<Device> findDevice(const std::function<bool(const std::shared_ptr<Device>&)>& filterFunction);
 
 /** Find devices with a custom filter */
 std::vector<std::shared_ptr<Device>> findDevices(const std::function<bool(const std::shared_ptr<Device>&)>& filterFunction);
 
-/** Find a device in the registry by its name. */
-std::shared_ptr<Device> _Nullable findDevice(std::string name);
+/** Find a device in the registry by its name. Could return nullptr if not found. */
+std::shared_ptr<Device> findDevice(std::string name);
 
-/** Find a device in the registry by its identifier. */
-std::shared_ptr<Device> _Nullable findDevice(Device::Id id);
+/** Find a device in the registry by its identifier. Could return nullptr if not found.*/
+std::shared_ptr<Device> findDevice(Device::Id id);
 
 /** Find 0, 1 or more devices in the registry by type. */
 std::vector<std::shared_ptr<Device>> findDevices(Device::Type type);
diff --git a/Modules/hal-device-module/Source/hal/Device.cpp b/Modules/hal-device-module/Source/hal/Device.cpp
index 2aab71b0..7b47a1de 100644
--- a/Modules/hal-device-module/Source/hal/Device.cpp
+++ b/Modules/hal-device-module/Source/hal/Device.cpp
@@ -88,7 +88,7 @@ std::vector<std::shared_ptr<Device>> findDevices(const std::function<bool(const
     return toVector(devices_view);
 }
 
-std::shared_ptr<Device> _Nullable findDevice(const std::function<bool(const std::shared_ptr<Device>&)>& filterFunction) {
+std::shared_ptr<Device> findDevice(const std::function<bool(const std::shared_ptr<Device>&)>& filterFunction) {
     auto scoped_mutex = mutex.asScopedLock();
     scoped_mutex.lock();
 
@@ -102,13 +102,13 @@ std::shared_ptr<Device> _Nullable findDevice(const std::function<bool(const std:
     }
 }
 
-std::shared_ptr<Device> _Nullable findDevice(std::string name) {
+std::shared_ptr<Device> findDevice(std::string name) {
     return findDevice([&name](auto& device){
         return device->getName() == name;
     });
 }
 
-std::shared_ptr<Device> _Nullable findDevice(Device::Id id) {
+std::shared_ptr<Device> findDevice(Device::Id id) {
     return findDevice([id](auto& device){
       return device->getId() == id;
     });
diff --git a/Tactility/CMakeLists.txt b/Tactility/CMakeLists.txt
index 51b1e994..647eae2e 100644
--- a/Tactility/CMakeLists.txt
+++ b/Tactility/CMakeLists.txt
@@ -62,9 +62,6 @@ else()
         PUBLIC Include/
     )
 
-    add_definitions(-D_Nullable=)
-    add_definitions(-D_Nonnull=)
-
     target_link_libraries(Tactility PUBLIC
         cJSON
         TactilityFreeRtos
diff --git a/Tactility/Include/Tactility/Tactility.h b/Tactility/Include/Tactility/Tactility.h
index 612694d2..4e2bc337 100644
--- a/Tactility/Include/Tactility/Tactility.h
+++ b/Tactility/Include/Tactility/Tactility.h
@@ -27,9 +27,10 @@ void run(const Configuration& config, Module* platformModule, Module* deviceModu
 
 /**
  * While technically nullable, this instance is always set if tt_init() succeeds.
+ * Could return nullptr if init was not called.
  * @return the Configuration instance that was passed on to tt_init() if init is successful
  */
-const Configuration* _Nullable getConfiguration();
+const Configuration* getConfiguration();
 
 /** Provides access to the dispatcher that runs on the main task.
  * @warning This dispatcher is used for WiFi and might block for some time during WiFi connection.
@@ -40,7 +41,7 @@ Dispatcher& getMainDispatcher();
 namespace hal {
 
 /** While technically this configuration is nullable, it's never null after initHeadless() is called. */
-const Configuration* _Nullable getConfiguration();
+const Configuration* getConfiguration();
 
 } // namespace hal
 
diff --git a/Tactility/Include/Tactility/app/App.h b/Tactility/Include/Tactility/app/App.h
index 5bab5804..e60bd591 100644
--- a/Tactility/Include/Tactility/app/App.h
+++ b/Tactility/Include/Tactility/app/App.h
@@ -44,7 +44,8 @@ public:
     virtual void onDestroy(AppContext& appContext) {}
     virtual void onShow(AppContext& appContext, lv_obj_t* parent) {}
     virtual void onHide(AppContext& appContext) {}
-    virtual void onResult(AppContext& appContext, LaunchId launchId, Result result, std::unique_ptr<Bundle> _Nullable resultData) {}
+    /** resultData could be null */
+    virtual void onResult(AppContext& appContext, LaunchId launchId, Result result, std::unique_ptr<Bundle> resultData) {}
 
     Mutex& getMutex() { return mutex; }
 
@@ -81,9 +82,9 @@ std::shared_ptr<App> create() { return std::shared_ptr<T>(new T); }
 /**
  * @brief Start an app
  * @param[in] id application name or id
- * @param[in] parameters optional parameters to pass onto the application
+ * @param[in] parameters optional parameters to pass onto the application. can be nullptr.
  */
-LaunchId start(const std::string& id, std::shared_ptr<const Bundle> _Nullable parameters = nullptr);
+LaunchId start(const std::string& id, std::shared_ptr<const Bundle> parameters = nullptr);
 
 /** @brief Stop the currently showing app. Show the previous app if any app was still running. */
 void stop();
@@ -103,10 +104,10 @@ void stopAll(const std::string& id);
 bool isRunning(const std::string& id);
 
 /** @return the currently running app context (it is only ever null before the splash screen is shown) */
-std::shared_ptr<AppContext> _Nullable getCurrentAppContext();
+std::shared_ptr<AppContext> getCurrentAppContext();
 
 /** @return the currently running app (it is only ever null before the splash screen is shown) */
-std::shared_ptr<App> _Nullable getCurrentApp();
+std::shared_ptr<App> getCurrentApp();
 
 bool install(const std::string& path);
 
diff --git a/Tactility/Include/Tactility/app/AppRegistration.h b/Tactility/Include/Tactility/app/AppRegistration.h
index 9890a016..dc6595d6 100644
--- a/Tactility/Include/Tactility/app/AppRegistration.h
+++ b/Tactility/Include/Tactility/app/AppRegistration.h
@@ -18,7 +18,7 @@ bool removeAppManifest(const std::string& id);
  * @param[in] id the manifest id
  * @return the application manifest if it was found
  */
-_Nullable std::shared_ptr<AppManifest> findAppManifestById(const std::string& id);
+std::shared_ptr<AppManifest> findAppManifestById(const std::string& id);
 
 /** @return a list of all registered apps. This includes user and system apps. */
 std::vector<std::shared_ptr<AppManifest>> getAppManifests();
diff --git a/Tactility/Include/Tactility/app/ElfApp.h b/Tactility/Include/Tactility/app/ElfApp.h
index b1dd61f2..6a3d9f35 100644
--- a/Tactility/Include/Tactility/app/ElfApp.h
+++ b/Tactility/Include/Tactility/app/ElfApp.h
@@ -8,20 +8,26 @@ namespace tt::app {
 
 typedef void* (*CreateData)();
 typedef void (*DestroyData)(void* data);
-typedef void (*OnCreate)(void* appContext, void* _Nullable data);
-typedef void (*OnDestroy)(void* appContext, void* _Nullable data);
-typedef void (*OnShow)(void* appContext, void* _Nullable data, lv_obj_t* parent);
-typedef void (*OnHide)(void* appContext, void* _Nullable data);
-typedef void (*OnResult)(void* appContext, void* _Nullable data, LaunchId launchId, Result result, Bundle* resultData);
+/** data is nullable */
+typedef void (*OnCreate)(void* appContext, void* data);
+/** data is nullable */
+typedef void (*OnDestroy)(void* appContext, void* data);
+/** data is nullable */
+typedef void (*OnShow)(void* appContext, void* data, lv_obj_t* parent);
+/** data is nullable */
+typedef void (*OnHide)(void* appContext, void* data);
+/** data is nullable, resultData is nullable. */
+typedef void (*OnResult)(void* appContext, void* data, LaunchId launchId, Result result, Bundle* resultData);
 
+/** All fields are nullable */
 void setElfAppParameters(
-    CreateData _Nullable createData,
-    DestroyData _Nullable destroyData,
-    OnCreate _Nullable onCreate,
-    OnDestroy _Nullable onDestroy,
-    OnShow _Nullable onShow,
-    OnHide _Nullable onHide,
-    OnResult _Nullable onResult
+    CreateData createData,
+    DestroyData destroyData,
+    OnCreate onCreate,
+    OnDestroy onDestroy,
+    OnShow onShow,
+    OnHide onHide,
+    OnResult onResult
 );
 
 std::shared_ptr<App> createElfApp(const std::shared_ptr<AppManifest>& manifest);
diff --git a/Tactility/Include/Tactility/file/FileLock.h b/Tactility/Include/Tactility/file/FileLock.h
index 06fc62f2..a7b61580 100644
--- a/Tactility/Include/Tactility/file/FileLock.h
+++ b/Tactility/Include/Tactility/file/FileLock.h
@@ -15,6 +15,6 @@ namespace tt::file {
  * @param[in] path the path to find a lock for
  * @return a lock instance when a lock was found, otherwise nullptr
  */
-std::shared_ptr<Lock> _Nullable findLock(const std::string& path);
+std::shared_ptr<Lock> findLock(const std::string& path);
 
 }
diff --git a/Tactility/Include/Tactility/hal/Configuration.h b/Tactility/Include/Tactility/hal/Configuration.h
index f78f2d56..bbaad9c5 100644
--- a/Tactility/Include/Tactility/hal/Configuration.h
+++ b/Tactility/Include/Tactility/hal/Configuration.h
@@ -31,7 +31,7 @@ struct Configuration {
      * Called before I2C/SPI/etc is initialized.
      * Used for powering on the peripherals manually.
      */
-    const InitBoot _Nullable initBoot = nullptr;
+    const InitBoot initBoot = nullptr;
 
     /** Init behaviour: default (esp_lvgl_port for ESP32, nothing for PC) or None (nothing on any platform). Only used in Tactility, not in TactilityHeadless. */
     const LvglInit lvglInit = LvglInit::Default;
diff --git a/Tactility/Include/Tactility/hal/display/DisplayDevice.h b/Tactility/Include/Tactility/hal/display/DisplayDevice.h
index d7da8716..7620dfd8 100644
--- a/Tactility/Include/Tactility/hal/display/DisplayDevice.h
+++ b/Tactility/Include/Tactility/hal/display/DisplayDevice.h
@@ -26,7 +26,8 @@ public:
     virtual bool isPoweredOn() const { return true; }
     virtual bool supportsPowerControl() const { return false; }
 
-    virtual std::shared_ptr<touch::TouchDevice> _Nullable getTouchDevice() = 0;
+    /** Could return nullptr if not started */
+    virtual std::shared_ptr<touch::TouchDevice> getTouchDevice() = 0;
 
     /** Set a value in the range [0, 255] */
     virtual void setBacklightDuty(uint8_t backlightDuty) { /* NO-OP */ }
@@ -40,10 +41,12 @@ public:
     virtual bool startLvgl() = 0;
     virtual bool stopLvgl() = 0;
 
-    virtual lv_display_t* _Nullable getLvglDisplay() const = 0;
+    /** Could return nullptr if not started */
+    virtual lv_display_t* getLvglDisplay() const = 0;
 
     virtual bool supportsDisplayDriver() const = 0;
-    virtual std::shared_ptr<DisplayDriver> _Nullable getDisplayDriver() = 0;
+    /** Could return nullptr if not supported */
+    virtual std::shared_ptr<DisplayDriver> getDisplayDriver() = 0;
 };
 
 } // namespace tt::hal::display
diff --git a/Tactility/Include/Tactility/hal/encoder/EncoderDevice.h b/Tactility/Include/Tactility/hal/encoder/EncoderDevice.h
index 14e6e7a8..7880c45a 100644
--- a/Tactility/Include/Tactility/hal/encoder/EncoderDevice.h
+++ b/Tactility/Include/Tactility/hal/encoder/EncoderDevice.h
@@ -17,7 +17,8 @@ public:
     virtual bool startLvgl(lv_display_t* display) = 0;
     virtual bool stopLvgl() = 0;
 
-    virtual lv_indev_t* _Nullable getLvglIndev() = 0;
+    /** Could return nullptr if not started */
+    virtual lv_indev_t* getLvglIndev() = 0;
 };
 
 }
diff --git a/Tactility/Include/Tactility/hal/gps/GpsDevice.h b/Tactility/Include/Tactility/hal/gps/GpsDevice.h
index 74b5b2ea..c9355e93 100644
--- a/Tactility/Include/Tactility/hal/gps/GpsDevice.h
+++ b/Tactility/Include/Tactility/hal/gps/GpsDevice.h
@@ -48,7 +48,7 @@ private:
 
     const GpsConfiguration configuration;
     RecursiveMutex mutex;
-    std::unique_ptr<Thread> _Nullable thread;
+    std::unique_ptr<Thread> thread;
     bool threadInterrupted = false;
     std::vector<GgaSubscription> ggaSubscriptions;
     std::vector<RmcSubscription> rmcSubscriptions;
diff --git a/Tactility/Include/Tactility/hal/keyboard/KeyboardDevice.h b/Tactility/Include/Tactility/hal/keyboard/KeyboardDevice.h
index 71630a09..7c996569 100644
--- a/Tactility/Include/Tactility/hal/keyboard/KeyboardDevice.h
+++ b/Tactility/Include/Tactility/hal/keyboard/KeyboardDevice.h
@@ -20,7 +20,8 @@ public:
     /** @return true when the keyboard currently is physically attached */
     virtual bool isAttached() const = 0;
 
-    virtual lv_indev_t* _Nullable getLvglIndev() = 0;
+    /** Could return nullptr if not started */
+    virtual lv_indev_t* getLvglIndev() = 0;
 };
 
 }
diff --git a/Tactility/Include/Tactility/hal/sdcard/SdCardDevice.h b/Tactility/Include/Tactility/hal/sdcard/SdCardDevice.h
index 208be2d7..a9588e24 100644
--- a/Tactility/Include/Tactility/hal/sdcard/SdCardDevice.h
+++ b/Tactility/Include/Tactility/hal/sdcard/SdCardDevice.h
@@ -67,8 +67,8 @@ public:
     bool isMounted(TickType_t timeout = kernel::MAX_TICKS) const { return getState(timeout) == State::Mounted; }
 };
 
-/** Return the SdCard device if the path is within the SdCard mounted path (path std::string::starts_with() check)*/
-std::shared_ptr<SdCardDevice> _Nullable find(const std::string& path);
+/** Return the SdCard device if the path is within the SdCard mounted path (path std::string::starts_with() check), otherwise return nullptr */
+std::shared_ptr<SdCardDevice> find(const std::string& path);
 
 /**
  * Attempt to find an SD card that the specified belongs to,
diff --git a/Tactility/Include/Tactility/hal/sdcard/SdmmcDevice.h b/Tactility/Include/Tactility/hal/sdcard/SdmmcDevice.h
index 113b60bb..e1e50e0d 100644
--- a/Tactility/Include/Tactility/hal/sdcard/SdmmcDevice.h
+++ b/Tactility/Include/Tactility/hal/sdcard/SdmmcDevice.h
@@ -82,7 +82,8 @@ public:
 
     State getState(TickType_t timeout) const override;
 
-    sdmmc_card_t* _Nullable getCard() { return card; }
+    /** return card when mounted, otherwise return nullptr */
+    sdmmc_card_t* getCard() { return card; }
 };
 
 }
diff --git a/Tactility/Include/Tactility/hal/sdcard/SpiSdCardDevice.h b/Tactility/Include/Tactility/hal/sdcard/SpiSdCardDevice.h
index 4ca1877e..61c80efd 100644
--- a/Tactility/Include/Tactility/hal/sdcard/SpiSdCardDevice.h
+++ b/Tactility/Include/Tactility/hal/sdcard/SpiSdCardDevice.h
@@ -29,7 +29,7 @@ public:
             gpio_num_t spiPinInt,
             MountBehaviour mountBehaviourAtBoot,
             /** When customLock is a nullptr, use the SPI default one */
-            std::shared_ptr<Lock> _Nullable customLock = nullptr,
+            std::shared_ptr<Lock> customLock = nullptr,
             std::vector<gpio_num_t> csPinWorkAround = std::vector<gpio_num_t>(),
             spi_host_device_t spiHost = SPI2_HOST,
             int spiFrequencyKhz = SDMMC_FREQ_DEFAULT
@@ -50,7 +50,7 @@ public:
         gpio_num_t spiPinWp; // Write-protect
         gpio_num_t spiPinInt; // Interrupt
         MountBehaviour mountBehaviourAtBoot;
-        std::shared_ptr<Lock> _Nullable customLock;
+        std::shared_ptr<Lock> customLock; // can be nullptr
         std::vector<gpio_num_t> csPinWorkAround;
         spi_host_device_t spiHost;
         bool formatOnMountFailed = false;
@@ -91,7 +91,8 @@ public:
 
     State getState(TickType_t timeout) const override;
 
-    sdmmc_card_t* _Nullable getCard() { return card; }
+    /** return card when mounted, otherwise return nullptr */
+    sdmmc_card_t* getCard() { return card; }
 };
 
 }
diff --git a/Tactility/Include/Tactility/hal/spi/Spi.h b/Tactility/Include/Tactility/hal/spi/Spi.h
index 4ca52f09..2a48acd2 100644
--- a/Tactility/Include/Tactility/hal/spi/Spi.h
+++ b/Tactility/Include/Tactility/hal/spi/Spi.h
@@ -24,7 +24,7 @@ struct Configuration {
     /** Whether configuration can be changed. */
     bool isMutable;
     /** Optional custom lock - otherwise creates one internally */
-    std::shared_ptr<Lock> _Nullable lock;
+    std::shared_ptr<Lock> lock;
 };
 
 enum class Status {
diff --git a/Tactility/Include/Tactility/hal/touch/TouchDevice.h b/Tactility/Include/Tactility/hal/touch/TouchDevice.h
index 9616aab6..84c97e31 100644
--- a/Tactility/Include/Tactility/hal/touch/TouchDevice.h
+++ b/Tactility/Include/Tactility/hal/touch/TouchDevice.h
@@ -22,11 +22,13 @@ public:
     virtual bool startLvgl(lv_display_t* display) = 0;
     virtual bool stopLvgl() = 0;
 
-    virtual lv_indev_t* _Nullable getLvglIndev() = 0;
+    /** Could return nullptr if not started */
+    virtual lv_indev_t* getLvglIndev() = 0;
 
     virtual bool supportsTouchDriver() = 0;
 
-    virtual std::shared_ptr<TouchDriver> _Nullable getTouchDriver() = 0;
+    /** Could return nullptr if not supported */
+    virtual std::shared_ptr<TouchDriver> getTouchDriver() = 0;
 };
 
 }
diff --git a/Tactility/Include/Tactility/hal/touch/TouchDriver.h b/Tactility/Include/Tactility/hal/touch/TouchDriver.h
index a14f3abb..4db3b2c7 100644
--- a/Tactility/Include/Tactility/hal/touch/TouchDriver.h
+++ b/Tactility/Include/Tactility/hal/touch/TouchDriver.h
@@ -11,13 +11,13 @@ public:
      *
      * @param[in] x array of X coordinates
      * @param[in] y array of Y coordinates
-     * @param[in] strength optional array of strengths
+     * @param[in] strength optional array of strengths (nullable)
      * @param[in] pointCount the number of points currently touched on the screen
      * @param[in] maxPointCount the maximum number of points that can be touched at once
      *
      * @return true when touched and coordinates are available
      */
-    virtual bool getTouchedPoints(uint16_t* x, uint16_t* y, uint16_t* _Nullable strength, uint8_t* pointCount, uint8_t maxPointCount) = 0;
+    virtual bool getTouchedPoints(uint16_t* x, uint16_t* y, uint16_t* strength, uint8_t* pointCount, uint8_t maxPointCount) = 0;
 };
 
 }
diff --git a/Tactility/Include/Tactility/service/ServiceRegistration.h b/Tactility/Include/Tactility/service/ServiceRegistration.h
index ed5c24a9..a23a882a 100644
--- a/Tactility/Include/Tactility/service/ServiceRegistration.h
+++ b/Tactility/Include/Tactility/service/ServiceRegistration.h
@@ -40,26 +40,26 @@ State getState(const std::string& id);
  * @param[in] id the id as defined in the manifest
  * @return the matching manifest or nullptr when it wasn't found
  */
-std::shared_ptr<const ServiceManifest> _Nullable findManifestById(const std::string& id);
+std::shared_ptr<const ServiceManifest> findManifestById(const std::string& id);
 
 /** Find a ServiceContext by its manifest id.
  * @param[in] id the id as defined in the manifest
  * @return the service context or nullptr when it wasn't found
  */
-std::shared_ptr<ServiceContext> _Nullable findServiceContextById(const std::string& id);
+std::shared_ptr<ServiceContext> findServiceContextById(const std::string& id);
 
 /** Find a Service by its manifest id.
  * @param[in] id the id as defined in the manifest
  * @return the service context or nullptr when it wasn't found
  */
-std::shared_ptr<Service> _Nullable findServiceById(const std::string& id);
+std::shared_ptr<Service> findServiceById(const std::string& id);
 
 /** Find a Service by its manifest id.
  * @param[in] id the id as defined in the manifest
  * @return the service context or nullptr when it wasn't found
  */
 template <typename T>
-std::shared_ptr<T> _Nullable findServiceById(const std::string& id) {
+std::shared_ptr<T> findServiceById(const std::string& id) {
     return std::static_pointer_cast<T>(findServiceById(id));
 }
 
diff --git a/Tactility/Include/Tactility/service/gps/GpsService.h b/Tactility/Include/Tactility/service/gps/GpsService.h
index 011bd378..4c1fc6c5 100644
--- a/Tactility/Include/Tactility/service/gps/GpsService.h
+++ b/Tactility/Include/Tactility/service/gps/GpsService.h
@@ -34,7 +34,8 @@ class GpsService final : public Service {
     bool startGpsDevice(GpsDeviceRecord& deviceRecord);
     static bool stopGpsDevice(GpsDeviceRecord& deviceRecord);
 
-    GpsDeviceRecord* _Nullable findGpsRecord(const std::shared_ptr<hal::gps::GpsDevice>& record);
+    /** return nullptr when not found */
+    GpsDeviceRecord* findGpsRecord(const std::shared_ptr<hal::gps::GpsDevice>& record);
 
     void onGgaSentence(hal::Device::Id deviceId, const minmea_sentence_gga& gga);
     void onRmcSentence(hal::Device::Id deviceId, const minmea_sentence_rmc& rmc);
diff --git a/Tactility/Include/Tactility/service/loader/Loader.h b/Tactility/Include/Tactility/service/loader/Loader.h
index aeee3725..de78ed41 100644
--- a/Tactility/Include/Tactility/service/loader/Loader.h
+++ b/Tactility/Include/Tactility/service/loader/Loader.h
@@ -62,10 +62,10 @@ public:
     /**
      * @brief Start an app given an app id and an optional bundle with parameters
      * @param id the app identifier
-     * @param parameters optional parameter bundle
+     * @param parameters optional parameter bundle (nullable)
      * @return the launch id
      */
-    app::LaunchId start(const std::string& id, std::shared_ptr<const Bundle> _Nullable parameters);
+    app::LaunchId start(const std::string& id, std::shared_ptr<const Bundle> parameters);
 
     /**
      * @brief Stops the top-most app (the one that is currently active shown to the user
@@ -85,8 +85,8 @@ public:
      */
     void stopAll(const std::string& id);
 
-    /** @return the AppContext of the top-most application */
-    std::shared_ptr<app::AppContext> _Nullable getCurrentAppContext();
+    /** @return the AppContext of the top-most application, or nullptr if no app is running. */
+    std::shared_ptr<app::AppContext> getCurrentAppContext();
 
     /** @return true if the app is running anywhere in the app stack (the app does not have to be the top-most one for this to return true) */
     bool isRunning(const std::string& id) const;
@@ -95,6 +95,7 @@ public:
     std::shared_ptr<PubSub<Event>> getPubsub() const { return pubsubExternal; }
 };
 
-std::shared_ptr<LoaderService> _Nullable findLoaderService();
+/** return the service or nullptr if it's not running */
+std::shared_ptr<LoaderService> findLoaderService();
 
 } // namespace
diff --git a/Tactility/Private/Tactility/app/AppInstance.h b/Tactility/Private/Tactility/app/AppInstance.h
index 3e54ee8f..f671392a 100644
--- a/Tactility/Private/Tactility/app/AppInstance.h
+++ b/Tactility/Private/Tactility/app/AppInstance.h
@@ -36,7 +36,7 @@ class AppInstance : public AppContext {
      * When these are stored in the app struct, the struct takes ownership.
      * Do not mutate after app creation.
      */
-    std::shared_ptr<const Bundle> _Nullable parameters;
+    std::shared_ptr<const Bundle> parameters;
 
     std::shared_ptr<App> app;
 
diff --git a/Tactility/Private/Tactility/service/gui/GuiService.h b/Tactility/Private/Tactility/service/gui/GuiService.h
index a3830774..9ae0f3da 100644
--- a/Tactility/Private/Tactility/service/gui/GuiService.h
+++ b/Tactility/Private/Tactility/service/gui/GuiService.h
@@ -39,7 +39,7 @@ class GuiService final : public Service {
     // App-specific
     std::shared_ptr<app::AppInstance> appToRender = nullptr;
 
-    lv_obj_t* _Nullable keyboard = nullptr;
+    lv_obj_t* keyboard = nullptr;
     lv_group_t* keyboardGroup = nullptr;
 
     bool isStarted = false;
diff --git a/Tactility/Private/Tactility/service/screenshot/Screenshot.h b/Tactility/Private/Tactility/service/screenshot/Screenshot.h
index 0e4dd641..2fe89576 100644
--- a/Tactility/Private/Tactility/service/screenshot/Screenshot.h
+++ b/Tactility/Private/Tactility/service/screenshot/Screenshot.h
@@ -48,7 +48,7 @@ public:
     void stop();
 };
 
-std::shared_ptr<ScreenshotService> _Nullable optScreenshotService();
+std::shared_ptr<ScreenshotService> optScreenshotService();
 
 } // namespace
 
diff --git a/Tactility/Source/Tactility.cpp b/Tactility/Source/Tactility.cpp
index 6cbbe713..94cec20a 100644
--- a/Tactility/Source/Tactility.cpp
+++ b/Tactility/Source/Tactility.cpp
@@ -376,7 +376,8 @@ void run(const Configuration& config, Module* platformModule, Module* deviceModu
     }
 }
 
-const Configuration* _Nullable getConfiguration() {
+/** return the configuration or nullptr if it's not initialized */
+const Configuration* getConfiguration() {
     return config_instance;
 }
 
diff --git a/Tactility/Source/app/App.cpp b/Tactility/Source/app/App.cpp
index 63a2a80c..5bb5839e 100644
--- a/Tactility/Source/app/App.cpp
+++ b/Tactility/Source/app/App.cpp
@@ -5,7 +5,7 @@ namespace tt::app {
 
 constexpr auto* TAG = "App";
 
-LaunchId start(const std::string& id, std::shared_ptr<const Bundle> _Nullable parameters) {
+LaunchId start(const std::string& id, std::shared_ptr<const Bundle> parameters) {
     const auto service = service::loader::findLoaderService();
     assert(service != nullptr);
     return service->start(id, std::move(parameters));
@@ -35,13 +35,13 @@ bool isRunning(const std::string& id) {
     return service->isRunning(id);
 }
 
-std::shared_ptr<AppContext> _Nullable getCurrentAppContext() {
+std::shared_ptr<AppContext> getCurrentAppContext() {
     const auto service = service::loader::findLoaderService();
     assert(service != nullptr);
     return service->getCurrentAppContext();
 }
 
-std::shared_ptr<App> _Nullable getCurrentApp() {
+std::shared_ptr<App> getCurrentApp() {
     const auto app_context = getCurrentAppContext();
     return (app_context !=  nullptr) ? app_context->getApp() : nullptr;
 }
diff --git a/Tactility/Source/app/AppRegistration.cpp b/Tactility/Source/app/AppRegistration.cpp
index 1fa97976..e2db7b4c 100644
--- a/Tactility/Source/app/AppRegistration.cpp
+++ b/Tactility/Source/app/AppRegistration.cpp
@@ -39,7 +39,7 @@ bool removeAppManifest(const std::string& id) {
     return app_manifest_map.erase(id) == 1;
 }
 
-_Nullable std::shared_ptr<AppManifest> findAppManifestById(const std::string& id) {
+std::shared_ptr<AppManifest> findAppManifestById(const std::string& id) {
     hash_mutex.lock();
     auto result = app_manifest_map.find(id);
     hash_mutex.unlock();
diff --git a/Tactility/Source/app/ElfApp.cpp b/Tactility/Source/app/ElfApp.cpp
index 384a9a99..59d99c8a 100644
--- a/Tactility/Source/app/ElfApp.cpp
+++ b/Tactility/Source/app/ElfApp.cpp
@@ -34,13 +34,13 @@ class ElfApp final : public App {
 public:
 
     struct Parameters {
-        CreateData _Nullable createData = nullptr;
-        DestroyData _Nullable destroyData = nullptr;
-        OnCreate _Nullable onCreate = nullptr;
-        OnDestroy _Nullable onDestroy = nullptr;
-        OnShow _Nullable onShow = nullptr;
-        OnHide _Nullable onHide = nullptr;
-        OnResult _Nullable onResult = nullptr;
+        CreateData createData = nullptr;
+        DestroyData destroyData = nullptr;
+        OnCreate onCreate = nullptr;
+        OnDestroy onDestroy = nullptr;
+        OnShow onShow = nullptr;
+        OnHide onHide = nullptr;
+        OnResult onResult = nullptr;
     };
 
     static void setParameters(const Parameters& parameters) {
@@ -202,13 +202,13 @@ size_t ElfApp::staticParametersSetCount = 0;
 std::shared_ptr<Lock> ElfApp::staticParametersLock = std::make_shared<Mutex>();
 
 void setElfAppParameters(
-    CreateData _Nullable createData,
-    DestroyData _Nullable destroyData,
-    OnCreate _Nullable onCreate,
-    OnDestroy _Nullable onDestroy,
-    OnShow _Nullable onShow,
-    OnHide _Nullable onHide,
-    OnResult _Nullable onResult
+    CreateData createData,
+    DestroyData destroyData,
+    OnCreate onCreate,
+    OnDestroy onDestroy,
+    OnShow onShow,
+    OnHide onHide,
+    OnResult onResult
 ) {
     ElfApp::setParameters({
         .createData = createData,
diff --git a/Tactility/Source/app/apphub/AppHubApp.cpp b/Tactility/Source/app/apphub/AppHubApp.cpp
index a6596024..bed3fa2d 100644
--- a/Tactility/Source/app/apphub/AppHubApp.cpp
+++ b/Tactility/Source/app/apphub/AppHubApp.cpp
@@ -30,7 +30,7 @@ class AppHubApp final : public App {
     std::vector<AppHubEntry> entries;
     Mutex mutex;
 
-    static std::shared_ptr<AppHubApp> _Nullable findAppInstance() {
+    static std::shared_ptr<AppHubApp> findAppInstance() {
         auto app_context = getCurrentAppContext();
         if (app_context->getManifest().appId != manifest.appId) {
             return nullptr;
diff --git a/Tactility/Source/app/i2cscanner/I2cScanner.cpp b/Tactility/Source/app/i2cscanner/I2cScanner.cpp
index 280142b5..e1156ede 100644
--- a/Tactility/Source/app/i2cscanner/I2cScanner.cpp
+++ b/Tactility/Source/app/i2cscanner/I2cScanner.cpp
@@ -71,7 +71,7 @@ public:
 };
 
 /** Returns the app data if the app is active. Note that this could clash if the same app is started twice and a background thread is slow. */
-std::shared_ptr<I2cScannerApp> _Nullable optApp() {
+std::shared_ptr<I2cScannerApp> optApp() {
     auto appContext = getCurrentAppContext();
     if (appContext != nullptr && appContext->getManifest().appId == manifest.appId) {
         return std::static_pointer_cast<I2cScannerApp>(appContext->getApp());
diff --git a/Tactility/Source/app/power/Power.cpp b/Tactility/Source/app/power/Power.cpp
index 571b7e21..7bf50b12 100644
--- a/Tactility/Source/app/power/Power.cpp
+++ b/Tactility/Source/app/power/Power.cpp
@@ -20,7 +20,7 @@ extern const AppManifest manifest;
 class PowerApp;
 
 /** Returns the app data if the app is active. Note that this could clash if the same app is started twice and a background thread is slow. */
-std::shared_ptr<PowerApp> _Nullable optApp() {
+std::shared_ptr<PowerApp> optApp() {
     auto appContext = getCurrentAppContext();
     if (appContext != nullptr && appContext->getManifest().appId == manifest.appId) {
         return std::static_pointer_cast<PowerApp>(appContext->getApp());
diff --git a/Tactility/Source/app/screenshot/Screenshot.cpp b/Tactility/Source/app/screenshot/Screenshot.cpp
index bf25fb0d..d5db25b8 100644
--- a/Tactility/Source/app/screenshot/Screenshot.cpp
+++ b/Tactility/Source/app/screenshot/Screenshot.cpp
@@ -49,7 +49,7 @@ public:
 
 
 /** Returns the app data if the app is active. Note that this could clash if the same app is started twice and a background thread is slow. */
-std::shared_ptr<ScreenshotApp> _Nullable optApp() {
+std::shared_ptr<ScreenshotApp> optApp() {
     auto appContext = getCurrentAppContext();
     if (appContext != nullptr && appContext->getManifest().appId == manifest.appId) {
         return std::static_pointer_cast<ScreenshotApp>(appContext->getApp());
diff --git a/Tactility/Source/app/systeminfo/SystemInfo.cpp b/Tactility/Source/app/systeminfo/SystemInfo.cpp
index e46d20b0..771c1cd3 100644
--- a/Tactility/Source/app/systeminfo/SystemInfo.cpp
+++ b/Tactility/Source/app/systeminfo/SystemInfo.cpp
@@ -274,7 +274,7 @@ extern const AppManifest manifest;
 
 class SystemInfoApp;
 
-static std::shared_ptr<SystemInfoApp> _Nullable optApp() {
+static std::shared_ptr<SystemInfoApp> optApp() {
     auto appContext = getCurrentAppContext();
     if (appContext != nullptr && appContext->getManifest().appId == manifest.appId) {
         return std::static_pointer_cast<SystemInfoApp>(appContext->getApp());
diff --git a/Tactility/Source/app/wifimanage/View.cpp b/Tactility/Source/app/wifimanage/View.cpp
index 159d839e..17a69f83 100644
--- a/Tactility/Source/app/wifimanage/View.cpp
+++ b/Tactility/Source/app/wifimanage/View.cpp
@@ -16,7 +16,7 @@ namespace tt::app::wifimanage {
 
 static const auto LOGGER = Logger("WifiManageView");
 
-std::shared_ptr<WifiManage> _Nullable optWifiManage();
+std::shared_ptr<WifiManage> optWifiManage();
 
 static uint8_t mapRssiToPercentage(int rssi) {
     auto abs_rssi = std::abs(rssi);
diff --git a/Tactility/Source/file/FileLock.cpp b/Tactility/Source/file/FileLock.cpp
index be8dfcb1..3af36820 100644
--- a/Tactility/Source/file/FileLock.cpp
+++ b/Tactility/Source/file/FileLock.cpp
@@ -5,7 +5,7 @@
 
 namespace tt::file {
 
-std::shared_ptr<Lock> _Nullable findLock(const std::string& path) {
+std::shared_ptr<Lock> findLock(const std::string& path) {
     return hal::sdcard::findSdCardLock(path);
 }
 
diff --git a/Tactility/Source/hal/sdcard/SdCard.cpp b/Tactility/Source/hal/sdcard/SdCard.cpp
index 78e75e21..8a284ea4 100644
--- a/Tactility/Source/hal/sdcard/SdCard.cpp
+++ b/Tactility/Source/hal/sdcard/SdCard.cpp
@@ -3,7 +3,7 @@
 
 namespace tt::hal::sdcard {
 
-std::shared_ptr<SdCardDevice> _Nullable find(const std::string& path) {
+std::shared_ptr<SdCardDevice> find(const std::string& path) {
     auto sdcards = findDevices<SdCardDevice>(Device::Type::SdCard);
     for (auto& sdcard : sdcards) {
         if (sdcard->isMounted() && path.starts_with(sdcard->getMountPath())) {
diff --git a/Tactility/Source/hal/usb/Usb.cpp b/Tactility/Source/hal/usb/Usb.cpp
index f8c1ceee..6138ff3c 100644
--- a/Tactility/Source/hal/usb/Usb.cpp
+++ b/Tactility/Source/hal/usb/Usb.cpp
@@ -20,7 +20,7 @@ struct BootModeData {
 static Mode currentMode = Mode::Default;
 static RTC_NOINIT_ATTR BootModeData bootModeData;
 
-sdmmc_card_t* _Nullable getCard() {
+sdmmc_card_t* getCard() {
     auto sdcards = findDevices<sdcard::SpiSdCardDevice>(Device::Type::SdCard);
 
     std::shared_ptr<sdcard::SpiSdCardDevice> usable_sdcard;
diff --git a/Tactility/Source/hal/usb/UsbTusb.cpp b/Tactility/Source/hal/usb/UsbTusb.cpp
index 12a550df..b20f6413 100644
--- a/Tactility/Source/hal/usb/UsbTusb.cpp
+++ b/Tactility/Source/hal/usb/UsbTusb.cpp
@@ -19,7 +19,7 @@
 static const auto LOGGER = tt::Logger("USB");
 
 namespace tt::hal::usb {
-    extern sdmmc_card_t* _Nullable getCard();
+    extern sdmmc_card_t* getCard();
 }
 
 enum {
diff --git a/Tactility/Source/service/ServiceRegistration.cpp b/Tactility/Source/service/ServiceRegistration.cpp
index 3e24e7b1..f13b0717 100644
--- a/Tactility/Source/service/ServiceRegistration.cpp
+++ b/Tactility/Source/service/ServiceRegistration.cpp
@@ -44,7 +44,7 @@ void addService(const ServiceManifest& manifest, bool autoStart) {
     addService(std::make_shared<const ServiceManifest>(manifest), autoStart);
 }
 
-std::shared_ptr<const ServiceManifest> _Nullable findManifestById(const std::string& id) {
+std::shared_ptr<const ServiceManifest> findManifestById(const std::string& id) {
     manifest_mutex.lock();
     auto iterator = service_manifest_map.find(id);
     auto manifest = iterator != service_manifest_map.end() ? iterator->second : nullptr;
@@ -52,7 +52,7 @@ std::shared_ptr<const ServiceManifest> _Nullable findManifestById(const std::str
     return manifest;
 }
 
-static std::shared_ptr<ServiceInstance> _Nullable findServiceInstanceById(const std::string& id) {
+static std::shared_ptr<ServiceInstance> findServiceInstanceById(const std::string& id) {
     manifest_mutex.lock();
     auto iterator = service_instance_map.find(id);
     auto service = iterator != service_instance_map.end() ? iterator->second : nullptr;
@@ -92,11 +92,11 @@ bool startService(const std::string& id) {
     return true;
 }
 
-std::shared_ptr<ServiceContext> _Nullable findServiceContextById(const std::string& id) {
+std::shared_ptr<ServiceContext> findServiceContextById(const std::string& id) {
     return findServiceInstanceById(id);
 }
 
-std::shared_ptr<Service> _Nullable findServiceById(const std::string& id) {
+std::shared_ptr<Service> findServiceById(const std::string& id) {
     auto instance = findServiceInstanceById(id);
     return instance != nullptr ? instance->getService() : nullptr;
 }
diff --git a/Tactility/Source/service/gps/GpsService.cpp b/Tactility/Source/service/gps/GpsService.cpp
index 359b0269..3b6d4975 100644
--- a/Tactility/Source/service/gps/GpsService.cpp
+++ b/Tactility/Source/service/gps/GpsService.cpp
@@ -17,7 +17,7 @@ constexpr bool hasTimeElapsed(TickType_t now, TickType_t timeInThePast, TickType
     return (now - timeInThePast) >= expireTimeInTicks;
 }
 
-GpsService::GpsDeviceRecord* _Nullable GpsService::findGpsRecord(const std::shared_ptr<GpsDevice>& device) {
+GpsService::GpsDeviceRecord* GpsService::findGpsRecord(const std::shared_ptr<GpsDevice>& device) {
     auto lock = mutex.asScopedLock();
     lock.lock();
 
diff --git a/Tactility/Source/service/loader/Loader.cpp b/Tactility/Source/service/loader/Loader.cpp
index da2c43a2..e72724f4 100644
--- a/Tactility/Source/service/loader/Loader.cpp
+++ b/Tactility/Source/service/loader/Loader.cpp
@@ -297,7 +297,7 @@ void LoaderService::stopAll(const std::string& id) {
     });
 }
 
-std::shared_ptr<app::AppContext> _Nullable LoaderService::getCurrentAppContext() {
+std::shared_ptr<app::AppContext> LoaderService::getCurrentAppContext() {
     const auto lock = mutex.asScopedLock();
     lock.lock();
     if (appStack.empty()) {
@@ -318,7 +318,7 @@ bool LoaderService::isRunning(const std::string& id) const {
     return false;
 }
 
-std::shared_ptr<LoaderService> _Nullable findLoaderService() {
+std::shared_ptr<LoaderService> findLoaderService() {
     return service::findServiceById<LoaderService>(manifest.id);
 }
 
diff --git a/Tactility/Source/service/screenshot/Screenshot.cpp b/Tactility/Source/service/screenshot/Screenshot.cpp
index 64d57a46..2a086c0d 100644
--- a/Tactility/Source/service/screenshot/Screenshot.cpp
+++ b/Tactility/Source/service/screenshot/Screenshot.cpp
@@ -16,7 +16,7 @@ static const auto LOGGER = Logger("ScreenshotService");
 
 extern const ServiceManifest manifest;
 
-std::shared_ptr<ScreenshotService> _Nullable optScreenshotService() {
+std::shared_ptr<ScreenshotService> optScreenshotService() {
     return service::findServiceById<ScreenshotService>(manifest.id);
 }
 
diff --git a/Tactility/Source/service/statusbar/Statusbar.cpp b/Tactility/Source/service/statusbar/Statusbar.cpp
index 34c6dca8..25fa22f7 100644
--- a/Tactility/Source/service/statusbar/Statusbar.cpp
+++ b/Tactility/Source/service/statusbar/Statusbar.cpp
@@ -90,7 +90,7 @@ static const char* getSdCardStatusIcon(hal::sdcard::SdCardDevice::State state) {
     }
 }
 
-static _Nullable const char* getPowerStatusIcon() {
+static const char* getPowerStatusIcon() {
     // TODO: Support multiple power devices?
     std::shared_ptr<hal::power::PowerDevice> power;
     hal::findDevices<hal::power::PowerDevice>(hal::Device::Type::Power, [&power](const auto& device) {
diff --git a/Tactility/Source/service/wifi/WifiEsp.cpp b/Tactility/Source/service/wifi/WifiEsp.cpp
index eac21186..b853b2eb 100644
--- a/Tactility/Source/service/wifi/WifiEsp.cpp
+++ b/Tactility/Source/service/wifi/WifiEsp.cpp
@@ -62,9 +62,9 @@ public:
     // for example: when scanning and you turn off the radio, the scan should probably stop or turning off
     // the radio should disable the on/off button in the app as it is pending.
     /** @brief The network interface when wifi is started */
-    esp_netif_t* _Nullable netif = nullptr;
+    esp_netif_t* netif = nullptr;
     /** @brief Scanning results */
-    wifi_ap_record_t* _Nullable scan_list = nullptr;
+    wifi_ap_record_t* scan_list = nullptr;
     /** @brief The current item count in scan_list (-1 when scan_list is NULL) */
     uint16_t scan_list_count = 0;
     /** @brief Maximum amount of records to scan (value > 0) */
diff --git a/TactilityC/CMakeLists.txt b/TactilityC/CMakeLists.txt
index 0e736321..d34e383e 100644
--- a/TactilityC/CMakeLists.txt
+++ b/TactilityC/CMakeLists.txt
@@ -19,9 +19,6 @@ else()
 
     add_library(TactilityC OBJECT)
 
-    add_definitions(-D_Nullable=)
-    add_definitions(-D_Nonnull=)
-
     target_sources(TactilityC PRIVATE ${SOURCES})
     include_directories(TactilityC PRIVATE Private/)
     target_include_directories(TactilityC PUBLIC Include/)
diff --git a/TactilityC/Include/tt_app.h b/TactilityC/Include/tt_app.h
index cefed07f..874cf4d6 100644
--- a/TactilityC/Include/tt_app.h
+++ b/TactilityC/Include/tt_app.h
@@ -22,46 +22,47 @@ typedef enum {
 
 typedef unsigned int AppLaunchId;
 
-/** Important: These function types must map to t::app types exactly */
+/** Important: These function types must map to t::app types exactly. All void* data is nullable. */
 typedef void* (*AppCreateData)();
 typedef void (*AppDestroyData)(void* data);
-typedef void (*AppOnCreate)(AppHandle app, void* _Nullable data);
-typedef void (*AppOnDestroy)(AppHandle app, void* _Nullable data);
-typedef void (*AppOnShow)(AppHandle app, void* _Nullable data, lv_obj_t* parent);
-typedef void (*AppOnHide)(AppHandle app, void* _Nullable data);
-typedef void (*AppOnResult)(AppHandle app, void* _Nullable data, AppLaunchId launchId, AppResult result, BundleHandle resultData);
+typedef void (*AppOnCreate)(AppHandle app, void* data);
+typedef void (*AppOnDestroy)(AppHandle app, void* data);
+typedef void (*AppOnShow)(AppHandle app, void* data, lv_obj_t* parent);
+typedef void (*AppOnHide)(AppHandle app, void* data);
+typedef void (*AppOnResult)(AppHandle app, void* data, AppLaunchId launchId, AppResult result, BundleHandle resultData);
 
+/** All callback types are nullable */
 typedef struct {
     /** The application can allocate data to re-use later (e.g. struct with state) */
-    AppCreateData _Nullable createData;
+    AppCreateData createData;
     /** If createData is specified, this one must be specified too */
-    AppDestroyData _Nullable destroyData;
+    AppDestroyData destroyData;
     /** Called when the app is launched (started) */
-    AppOnCreate _Nullable onCreate;
+    AppOnCreate onCreate;
     /** Called when the app is exited (stopped) */
-    AppOnDestroy _Nullable onDestroy;
+    AppOnDestroy onDestroy;
     /** Called when the app is about to be shown to the user (app becomes visible) */
-    AppOnShow _Nullable onShow;
+    AppOnShow onShow;
     /** Called when the app is about to be invisible to the user (e.g. other app was launched by this app, and this app goes to the background) */
-    AppOnHide _Nullable onHide;
+    AppOnHide onHide;
     /** Called when the app receives a result after launching another app */
-    AppOnResult _Nullable onResult;
+    AppOnResult onResult;
 } AppRegistration;
 
 /** This is used to register the manifest of an external app. */
 void tt_app_register(const AppRegistration app);
 
 /** @return the bundle that belongs to this application, or null if it wasn't started with parameters. */
-BundleHandle _Nullable tt_app_get_parameters(AppHandle handle);
+BundleHandle tt_app_get_parameters(AppHandle handle);
 
 /**
  * Set the result before closing an app.
  * The result and bundle are passed along to the app that launched this app, when this app is closed.
  * @param[in] handle the app handle to set the result for
  * @param[in] result the result state to set
- * @param[in] bundle the result bundle to set
+ * @param[in] bundle the result bundle to set (can be null)
  */
-void tt_app_set_result(AppHandle handle, AppResult result, BundleHandle _Nullable bundle);
+void tt_app_set_result(AppHandle handle, AppResult result, BundleHandle bundle);
 
 /** @return true if a result was set for this app context */
 bool tt_app_has_result(AppHandle handle);
diff --git a/TactilityC/Source/tt_app.cpp b/TactilityC/Source/tt_app.cpp
index e87ec87b..24f6f001 100644
--- a/TactilityC/Source/tt_app.cpp
+++ b/TactilityC/Source/tt_app.cpp
@@ -32,11 +32,11 @@ void tt_app_register(
 #endif
 }
 
-BundleHandle _Nullable tt_app_get_parameters(AppHandle handle) {
+BundleHandle tt_app_get_parameters(AppHandle handle) {
     return (BundleHandle)HANDLE_AS_APP_CONTEXT(handle)->getParameters().get();
 }
 
-void tt_app_set_result(AppHandle handle, AppResult result, BundleHandle _Nullable bundle) {
+void tt_app_set_result(AppHandle handle, AppResult result, BundleHandle bundle) {
     auto shared_bundle = std::unique_ptr<tt::Bundle>(static_cast<tt::Bundle*>(bundle));
     HANDLE_AS_APP_CONTEXT(handle)->getApp()->setResult(static_cast<tt::app::Result>(result), std::move(shared_bundle));
 }
diff --git a/TactilityC/Source/tt_hal_touch.cpp b/TactilityC/Source/tt_hal_touch.cpp
index fd105553..9572275d 100644
--- a/TactilityC/Source/tt_hal_touch.cpp
+++ b/TactilityC/Source/tt_hal_touch.cpp
@@ -35,7 +35,7 @@ void tt_hal_touch_driver_free(TouchDriverHandle handle) {
     delete wrapper;
 }
 
-bool tt_hal_touch_driver_get_touched_points(TouchDriverHandle handle, uint16_t* x, uint16_t* y, uint16_t* _Nullable strength, uint8_t* pointCount, uint8_t maxPointCount) {
+bool tt_hal_touch_driver_get_touched_points(TouchDriverHandle handle, uint16_t* x, uint16_t* y, uint16_t* strength, uint8_t* pointCount, uint8_t maxPointCount) {
     DriverWrapper* wrapper = static_cast<DriverWrapper*>(handle);
     return wrapper->driver->getTouchedPoints(x, y, strength, pointCount, maxPointCount);
 }
diff --git a/TactilityCore/CMakeLists.txt b/TactilityCore/CMakeLists.txt
index 1824f94d..47f47aa3 100644
--- a/TactilityCore/CMakeLists.txt
+++ b/TactilityCore/CMakeLists.txt
@@ -23,9 +23,6 @@ else()
 
     target_include_directories(TactilityCore PUBLIC Include/)
 
-    add_definitions(-D_Nullable=)
-    add_definitions(-D_Nonnull=)
-
     target_link_libraries(TactilityCore PUBLIC
         TactilityFreeRtos
         TactilityKernel
diff --git a/TactilityCore/Include/Tactility/file/File.h b/TactilityCore/Include/Tactility/file/File.h
index fa102d99..0f2371e2 100644
--- a/TactilityCore/Include/Tactility/file/File.h
+++ b/TactilityCore/Include/Tactility/file/File.h
@@ -151,15 +151,15 @@ bool listDirectory(
  *
  * @param[in] path path the scan for files and directories
  * @param[out] outList a pointer to vector of dirent
- * @param[in] filter an optional filter to filter out specific items
- * @param[in] sort an optional sorting function
+ * @param[in] filter an optional filter to filter out specific items (nullable)
+ * @param[in] sort an optional sorting function (nullable)
  * @return the amount of items that were stored in "output" or -1 when an error occurred
  */
 int scandir(
     const std::string& path,
     std::vector<dirent>& outList,
-    ScandirFilter _Nullable filter = nullptr,
-    ScandirSort _Nullable sort = nullptr
+    ScandirFilter filter = nullptr,
+    ScandirSort sort = nullptr
 );
 
 bool readLines(const std::string& filePath, bool stripNewLine, std::function<void(const char* line)> callback);
diff --git a/TactilityCore/Source/file/File.cpp b/TactilityCore/Source/file/File.cpp
index c84bc86a..e45c6c4b 100644
--- a/TactilityCore/Source/file/File.cpp
+++ b/TactilityCore/Source/file/File.cpp
@@ -92,8 +92,8 @@ bool listDirectory(
 int scandir(
     const std::string& path,
     std::vector<dirent>& outList,
-    ScandirFilter _Nullable filterMethod,
-    ScandirSort _Nullable sortMethod
+    ScandirFilter filterMethod,
+    ScandirSort sortMethod
 ) {
     auto lock = getLock(path)->asScopedLock();
     lock.lock();
diff --git a/TactilityFreeRtos/Include/Tactility/Thread.h b/TactilityFreeRtos/Include/Tactility/Thread.h
index 552cc817..c34263dd 100644
--- a/TactilityFreeRtos/Include/Tactility/Thread.h
+++ b/TactilityFreeRtos/Include/Tactility/Thread.h
@@ -155,7 +155,7 @@ public:
         mutex.unlock();
     }
 
-    void setStateCallback(StateCallback callback, _Nullable void* callbackContext = nullptr) {
+    void setStateCallback(StateCallback callback, void* callbackContext = nullptr) {
         mutex.lock();
         assert(state == State::Stopped);
         stateCallback = callback;
diff --git a/Tests/Tactility/CMakeLists.txt b/Tests/Tactility/CMakeLists.txt
index 984bab9c..818ba286 100644
--- a/Tests/Tactility/CMakeLists.txt
+++ b/Tests/Tactility/CMakeLists.txt
@@ -7,9 +7,6 @@ set(CMAKE_CXX_COMPILER g++)
 file(GLOB_RECURSE TEST_SOURCES ${PROJECT_SOURCE_DIR}/*.cpp)
 add_executable(TactilityTests EXCLUDE_FROM_ALL ${TEST_SOURCES})
 
-add_definitions(-D_Nullable=)
-add_definitions(-D_Nonnull=)
-
 target_include_directories(TactilityTests PRIVATE
     ${DOCTESTINC}
 )
diff --git a/Tests/TactilityCore/CMakeLists.txt b/Tests/TactilityCore/CMakeLists.txt
index 550cedfe..a97a301b 100644
--- a/Tests/TactilityCore/CMakeLists.txt
+++ b/Tests/TactilityCore/CMakeLists.txt
@@ -7,9 +7,6 @@ set(CMAKE_CXX_COMPILER g++)
 file(GLOB_RECURSE TEST_SOURCES ${PROJECT_SOURCE_DIR}/*.cpp)
 add_executable(TactilityCoreTests EXCLUDE_FROM_ALL ${TEST_SOURCES})
 
-add_definitions(-D_Nullable=)
-add_definitions(-D_Nonnull=)
-
 target_include_directories(TactilityCoreTests PRIVATE
     ${DOCTESTINC}
 )
diff --git a/Tests/TactilityFreeRtos/CMakeLists.txt b/Tests/TactilityFreeRtos/CMakeLists.txt
index 788f2f67..883244e4 100644
--- a/Tests/TactilityFreeRtos/CMakeLists.txt
+++ b/Tests/TactilityFreeRtos/CMakeLists.txt
@@ -7,9 +7,6 @@ set(CMAKE_CXX_COMPILER g++)
 file(GLOB_RECURSE TEST_SOURCES ${PROJECT_SOURCE_DIR}/*.cpp)
 add_executable(TactilityFreeRtosTests EXCLUDE_FROM_ALL ${TEST_SOURCES})
 
-add_definitions(-D_Nullable=)
-add_definitions(-D_Nonnull=)
-
 target_include_directories(TactilityFreeRtosTests PRIVATE
     ${DOCTESTINC}
 )