What are some alternatives?
When comparing Touch Pianist and Pianu, you can also consider the following products
Simply Piano - Fast and fun way to learn piano
Synthesia - A fun way to learn how to play the piano.
Type Drummer - Drum by typing
Flowkey - The easiest way to learn piano with your iPhone or iPad
lightnote - An interactive site to learn the basics of music theory 🎶
Keezy Drummer - Make a beat in seconds