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

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

Galileo Organ 2 is a tonewheel and transistor organ app.

FM4 is a four operator FM synthesizer for iPad.

FM TiNES is an electric piano library dedicated to the most beautiful FM electric pianos ever made.

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

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.

Englitina is an authentic-sounding English Treble Concertina for the iPad.

Electric Vintage is a virtual instrument based on a reproduction of a famous vintage electric piano (1976).

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

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

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.

Cube Synth is a groundbreaking new software instrument giving you the power and flexibility of additive synthesis together with easy editing and morphing capabilities.

Combo Organ Model V is a musical keyboard app for iPad/iPhone/iPod touch that simulates the electric transistor organ, is called a Combo Organ. It was a big success in the 1960s.

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")!

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

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.

Portable Music Production Studio : create beats, compose whole tracks, sample, record, sequence, perform, mix and arrange your own music.