iOS Musician Apps (115) Supported Technologies is Inter-App Audio (IAA), Instrument Sounds is Keyboards

Fed up with standardized presets and instruments? Feel lost in overcomplex filters and effects? Don’t wanna sound like everyone else? BLEASS is just the right instrument for you: it unleashes your inner musical creativity by bringing music production and performance to its very core: play, perform, compose beats and melodies in a new yet intuitive way thanks to its multitrack sequencer, synthesizer and drum machine.

LCW-2 mono is a little complicated synthesizer based on ToyTone and implements several experimental functions.

AudioKit Synth One is a completely free & open-source professional iOS Synthesizer. 

Modulin is a customizable synthesizer. It allows for unique personal expression while providing a wide spectrum of visual feedback.

Wotja X is a new cross-platform interface for the 'Wotja Generative Music System'.

Free iPad instrument featuring the classic sounds of famous 80s FM Synthesizers.

Groovebox is a free music studio app packed with synths and drum machines.

AutoArp turns your iPhone (or iPod Touch) into a musical instrument that is halfway between a traditional auto-harp zither and an arpeggiated analogue-style synth.

SynthMaster Player for iPad is the MOBILE PLAYER VERSION of the award winning SynthMaster software synthesizer.

Nanologue boasts a wide scope of inspiring sounds and professional sound effects, sporting a straightforward multi-touch interface and a great-sounding monophonic synthesizer.

Colossus Piano sets a new standard in terms of realism, detail and overall quality of piano sounds on your iPad, iPhone and iPod touch.

CHAiOS SYNTH 2 is a synthesizer/melody generator that creates unique melodies with just one tap.

The concert quality piano app.

ToyTone is simple synthesizer. Select waveform, and move the slider. Tap the pad at bottom, you can play.

The concert quality piano app.