We created an app that enjoyed using. We love our synths so we made this app which is half drum machine, half music sequencer. It is designed exclusively for electronic music lovers. There are lots of drum sounds to choose from and its really quick to get some loops going. Then are also dedicated bass, synth and chord/pad tracks each with many sounds to choose from. You just choose where you want the note, what note and what sound. The music tracks also have pitch modulation for detuned or tremolo effects. You can make slidey basses or wobbly atmospheric pads.
More info here and a couple of videos at beatsnbobs website
We hope its the first of many.