Auxy Music Studio - Auxy brings real music creation to iPhone in a simple and inspiring format.
ReCycle - ReCycle is a creative tool that helps you make the most of your grooves.
cassini - Polyphonic Synthesizer for iPhone/iPod touch
VICE - Bring loops to life with the loop slicer plugin for Mac and Windows.
zMors Modular - Full featured modular synthesizer for iOS
Looperator - Looperator is a Multi-Effect Sequencer, chopping any audio input at the transients.