Leverkühn Apps has released GetPro for iOS. This app provides the possibility of playing chords belonging to a key with the intention of generating chord progressions and musical ideas to help in your song writing.
The idea behind this app is not to create a musical instrument, but rather it is a tool to create songs quickly and easily or help you generate ideas for your compositions. This way, with just one finger you can play chords belonging to the same key.
Each key has the 6 chords of the harmonized scale with the numerical system I, II, III, IV, V and VI. The screen shows 6 natural chords, 6 seventh chords and 6 "sus" and 9 chords. A total of 18 different chords are available for each key.
The screen menu shows the most common five keys in contemporary music.; C, G, D, A and F. When you play each chord with your finger, you can hear it with a piano sound.