Do you nearly need to price the iPhone version separately?
This app is trying to go further than the original desktop chordieapp by madkat music. Yes that is fine and commended. Though not entirely original as there a few around on iOS already doing that. Not to mention Scaler which has hundreds of curated chord packs for free. But pricing this separately for the iPhone make no sense, and charging people for chord progressions is greedy. As a developer it is not a great stretch to support all devices. Apple has done the heavy lifting for you already.