Marble Music
Native iOS, in progress. Coming to the App Store.
Marble Music is marbles, gravity, and notes.
The app is free and shows a small banner ad you can remove. Restore Purchases is on the TUNE screen.
Also from Aqua Mobilis: Kelp Studio · DUET Synth · Anemone · Tape Eater · Bloom · Ghost98 · Buoy · Trench