What are some alternatives?
When comparing Piano Academy 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.
Flowkey - The easiest way to learn piano with your iPhone or iPad
Chroma - Welcome to Chroma Cutlery Cnife - Manufacturer of kitchen knives, includes products and contact information.
Melodics - Melodics is a desktop app that teaches you to play MIDI keyboards, pad controllers, and drums.
Scale Search by Solfej - Searchable library of over 6000 different scales