Auxy Music Studio - Auxy brings real music creation to iPhone in a simple and inspiring format.
Until AM - DJ in your browser with this SoundCloud music mixer
cassini - Polyphonic Synthesizer for iPhone/iPod touch
Songlio - Free musical guessing game: race friends to name that tune
zMors Modular - Full featured modular synthesizer for iOS
Fretello Stage - Jam, record and share your music in the blink of an eye