Auxy Music Studio - Auxy brings real music creation to iPhone in a simple and inspiring format.
Ripple Maker - A coffee machine that turns selfies & photos into latte art
cassini - Polyphonic Synthesizer for iPhone/iPod touch
nlog Synth - Professional Virtual Analogue Synthesizer ::: check nlogmusic at YouTube :::
Jasuto - Download Jasuto, a Modular Synthesizer app, for iOS and Android devices. Jasuto allows you to visually construct your own synths/effects and use them to make sequences all on your iPhone, iPad or Android device.
Surge XT - Open-source subtractive-hybrid synthesizer formerly sold commercially as Vember Audio Surge.