This is the official keyboard for Key Mapper that has on-screen buttons!
Key Mapper GUI Keyboard is a fork of OpenBoard, which is a 100% foss keyboard based on AOSP. The keyboard built in to Key Mapper is called the "Basic Input Method" and does NOT have a GUI.
Comments will not be approved to be posted if they are SPAM, abusive, off-topic, use profanity, contain a personal attack, or promote hate of any kind.