Turn your rooted Android phone into a USB keyboard + trackpad. Plug into any computer via USB cable, open the app, type.

• Ortholinear keyboard — full QWERTY grid layout, F-keys, modifiers, arrows, nav keys
• Trackpad — swipe to move cursor, tap for left click, two-finger swipe for scroll
• L/M/R click buttons below trackpad
• Text blast — type into the text field and hit Send to output a string as keystrokes
• Side swap — tap ⇄ to move trackpad between left/right side
• Landscape-only, fullscreen, immersive
• 21KB APK, zero dependencies

• Rooted Android phone (KernelSU, Magisk, etc.)
• USB gadget configfs support (most phones have this)
• SELinux permissive (or appropriate policy for /dev/hidg0)

The app configures a USB HID composite gadget via configfs with two Report IDs:

• Report ID 1: Keyboard (8-byte boot protocol)
• Report ID 2: Mouse (buttons + relative X/Y/wheel)

Both go through a single /dev/hidg0 device. The host computer sees a standard USB keyboard and mouse — no drivers needed.

# Requires Android SDK (build-tools + a platform android-34 or newer).
# build.sh auto-detects the newest installed build-tools/platform; pin with
# BUILD_TOOLS_VERSION / COMPILE_SDK if you need a specific pair.
bash build.sh
# Output: build/PhoneKB.apk

Pure (framework-independent) logic — the HID keymap, modifier bitmask, and mouse-delta clamping in com.phonekb.HidMap — has JUnit tests that run on a plain JDK with no Android SDK, emulator, or device:

bash run-tests.sh

This fetches JUnit 4 into .testlibs/ (gitignored) on first run. UI / Activity / Bluetooth code is not covered — that would need an instrumented device test, which isn't part of this suite.

.github/workflows/ci.yml runs the unit tests and builds a debug APK on every push and pull request (uploaded as a build artifact). This is the first environment that compiles the app from source in CI.

adb install PhoneKB.apk

The HID gadget must be configured once per boot (requires root):

# Via ADB or Termux with root:
su -c 'sh setup-hid.sh'

The app attempts this automatically on launch if su is available.

MIT