This application is a musical instrument, but it doesnt make any sounds by itself. It sends the notes you play to other music apps on your iPad.
This means you can use it to play any instruments which support virtual MIDI, including those in Garageband.
You play this instrument by using the buttons to move up and down through different patterns of notes, known as scales.
There are full instructions in the app to help get you started.
We have many more features planned such as iPhone support, creating your own scales and generative composition tools, so look out for future updates!