ReSlice - Slice your audio with an advanced, rhythmic arpeggiator and FX.
Gnoosic - Even if you don't know what you are looking for - gnod will find it.
cassini - Polyphonic Synthesizer for iPhone/iPod touch
BandNext - Discover bands that sound similar to artists you already love with BandNext. A single click saves your results to a Youtube playlist.
nlog Synth - Professional Virtual Analogue Synthesizer ::: check nlogmusic at YouTube :::
Musicroamer - A visual Pandora for discovering new music