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.
Mini Piano - Mini Piano is a fun on the go App which you can use right off the bat with its intuitive interface...
Playground Sessions - Online piano learning game.
Piano Time - Piano Time is a multitouch piano with 36 visible keys and 4 selectable octaves.