A small app for playing the piano on a virtual keyboard, and you can set chords for auto-playing in the background.
This app can be deployed for desktop, android, html5, and possibly other platforms supported by libgdx.
The app was made using the Libgdx game development framework: https://libgdx.badlogicgames.com/
Midi sounds on android can be credited to billthefarmer's midi driver project at https://github.com/billthefarmer/mididriver
First version made at 2012, major update at 2016