What are some alternatives?
When comparing Jameasy for Violin 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.
Yousician - An interactive guitar-learning app.
Flowkey - The easiest way to learn piano with your iPhone or iPad
alphaTab - alphaTab is a cross platform music notation and guitar tablature rendering library.
Playground Sessions - Online piano learning game.