Thanks to Frankie at Autocratik I’ve been messing around with Figure, which is a simple synth for iOS.
The UI is gorgeous and for such a simple thing you can create quite a broad range of music with it. It takes a straight forward pattern based approach to adjusting the beat style or scale used. So you can select a pattern for you bass drum or your lead synth and just mess around with it. It makes good use of the multi-touch screen allowing you to vary the note volume or subtly alter the tone of the drums. It uses a similar touch and drag interface for modifying the lead and bass characteristics to.
Here’s a couple of loops I’ve created:
The random song name generator is also pretty sweet!