Key Mapper GUI Keyboard is an Android app developed by sds100, available for free in the Utilities & Tools category. It is the official keyboard for Key Mapper and provides a Graphical User Interface with on-screen buttons. However, it is only compatible with Key Mapperor newer.

The app is easy to use and provides a comfortable typing experience. The on-screen buttons are well-designed and responsive. It is a great addition to Key Mapper and makes typing on Android devices a lot easier. The app is lightweight and does not take up much space on the device.

Overall, Key Mapper GUI Keyboard is a must-have for users of Key Mapper who want a better typing experience. The app provides a user-friendly interface and is highly recommended for anyone looking to improve their typing on Android devices.