Myself and two friends have tried to make music production easier (and more robust) on the phone in our spare time, and came up with our iPhone app, Tize (https://itunes.apple.com/us/app/tize-make-music-beats-easy/i...), to that end.

If it sounds like something you're interested in please give it a go! We're always working to improve it and open to feedback. (Android is coming soon)