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

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

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

Mimicking the layout of Hohner's iconic chromatic button accordions (CBA), both B-System (Bayan) and C-System, this intuitive virtual accordion is easy to play and sounds exactly like the real instrument.

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

Based on Hohner's iconic Corona Classic diatonic accordion, this virtual accordion app plays in all five of the most popular tones: EAD (Mi), FBbEb (Fa), GCF (Sol), ADG, and BbEbAb.

Mimicking the layout of Hohner's iconic piano accordions, this intuitive virtual accordion is easy to play and sounds exactly like the real instrument.

The Optigan, short for Optical Organ, was a chord organ from the early 1970’s.

SpectrumGen is a spectral synthesizer with a simple and effective user interface.

PixelWave is an experimental synth with old school pixel interface.

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.

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

Photophore is a unique instrument that uses flocks of up to 100 sound generators to create rich, organic synthesizer sounds.

With this instrument you can transform any sound into a playable musical instrument via a technique known as Granular Synthesis.

iSEM is a recreation of the classic 1974 Oberheim SEM (Synthesizer Expander Module), one of the world's first self-contained synthesizer modules and the first to bear the "Oberheim Electronics" name.

Triqtraq LE is a free limited edition of the critically acclaimed music app Triqtraq - Jam Sequencer.

Compose original beats in the smooth one-window interface, record sound tweaks in realtime and sample your own sounds for direct use.

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

When a punchy, fat sound is demanded, look no further. iProphet recreates the unique sound of the classic Sequential Circuits Prophet VS synthesizer.

iMini is a recreation of the legendary synthesizer created by Bob Moog in 1971, one of most iconic synthesizers of all time.

Esoteric Synth is a unusual generator of synthetic sound events. The synthesis is based on 5 oscillators which are intersected through an multiple amplitude modulation and multiple frequency modulation making  an high sound variability. This App is suitable to generate complex sound textures, glitches, noises, sound clouds, sound drones, point sounds and more.