What are some alternatives?
When comparing Touch Pianist and Piano Notes Fun, you can also consider the following products
Simply Piano - Fast and fun way to learn piano
Yousician - An interactive guitar-learning app.
Pianu - Learn to play the piano in your browser.
Type Drummer - Drum by typing
Melodics - Melodics is a desktop app that teaches you to play MIDI keyboards, pad controllers, and drums.
lightnote - An interactive site to learn the basics of music theory 🎶