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

Flynth is a synthesizer by Fingerlab, designed for musicality and easy use.

Mellowsound is an emulation of a legendary instrument, a keyboard sampler from the 60s used by many famous artists like the Beatles, David Bowie, Radiohead and many others, this mythic instrument is called The Mellotron.

Tardigrain is a granular synthesizer. Sounds are created by taking smaller fragments of a sample and playing them back in a non linear fashion, with settings for grain size, direction, step size and more.

Elsa is a retro style sampling keyboard with tempo based looping.

Shape is a polyphonic synthesiser allowing the user to draw the shape of the oscillator waveform.

With EGSY01 you can create sounds, from modern ones to vintage analog ones, working with arpeggiator, step sequencer and FM, addictive and subtractive synthesis.

Electro-Harmonix, a pioneer since 1968 in the field of sound effects pedals for musicians, has produced an app which is a faithful digital re-creation of their circa 1980 analog cult-classic, The MINI-SYNTHESIZER.

An app which is a faithful digital re-creation of their circa 1980 analog cult-classic, The MINI-SYNTHESIZER.

Pure Piano is a professional, multi-sampled concert grand piano with a unique Morph Pad that allows you to explore a multitude of sounds ranging from mellow and intimate tones to surreal, cinematic textures.

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.

Poison-202 is a professional Vintage Midi Synthesizer.

SpringSound is a physical-modeling audio synthesizer that produces sounds by simulating interactions and vibrations of a set of activators and masses connected to springs.

Play with the sound of a full cathedral organ, created by award-winning sound designer Kurt Ader.

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

The second best sounding piano app in the App Store (after "Colossus Piano")!

This app reproduces the functionality of Casio’s best-selling CZ-series models, such as the CZ-101 (first released in 1984), and also includes new functions.

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.

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

Epic 64-voice Virtual Analog / PCM iPad Synth. Inspired by the Digital Synths of the 80s and 90s.

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