iOS Musician Apps (48) Instrument Sounds is Keyboards, Free

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

Pure Synth® Platinum is a full-blown rompler/synthesizer for your iOS device. Neither the synth engine or the sample engine is an afterthought: Both engines are fully capable and feature-rich. The romper section contains a well rounded assortment of analog, synth, string, digital, and acoustic instruments.

Turbosounds for Accordion provides many special sounds of the Oberkrainer folk music.

Made for complex and organic sounds, Factory sports a big modulation matrix with all kinds of features to create a wildlife of sounds. A vast array of DSP is ready to play: Analog style oscillators and filters, but also different flavors of wavetable synthesis, Wavetable driven Waveguide resonators and a 3-FX-Chain in a dynamic signal flow.

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.

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

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

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