SquareSynth

SquareSynth is an 8-bit synthesizer for iOS.

SquareAcid

This is an “Acid Synth” synthesizer. It makes sounds similar to TB-303 synth.

Freesound Safari lets users search, save, and download audio files from Freesound.org.

Loop Builder lets users play and sequence audio files, in a loop-based sequencer.

This app lets you chop up an audio file, by using up to 16 cue points.