Auxy Music Studio - Auxy brings real music creation to iPhone in a simple and inspiring format.
Giada - Giada is a free, minimal, hardcore audio tool for DJs, live performers and electronic musicians.
cassini - Polyphonic Synthesizer for iPhone/iPod touch
JAM - Shake your sound - Music motion app. Make music by shaking your phone. 🎶
nlog Synth - Professional Virtual Analogue Synthesizer ::: check nlogmusic at YouTube :::
Blocs Wave - A free audio app for creating music loops.