Flowkey - The easiest way to learn piano with your iPhone or iPad
Musicope - The Piano Game. Contribute to oldrich-s/musicope development by creating an account on GitHub.
Pianu - Learn to play the piano in your browser.
Synthesia - A fun way to learn how to play the piano.
Playground Sessions - Online piano learning game.
Piano From Above - Piano From Above is a program that turns learning the piano into a videogame.