iOS Musician Apps (56) Instrument Type is Synth, Free

Featuring an FM tone generator, FM Essential is a synthesizer app that provides for real-time synth performances and also lets you edit voices.

Flexible and powerful frequency generator.

Spectrum is a collection of Audio Unit ports of popular eurorack synthesizer modules.

iTuttle is a Subtractive Monophonic/Paraphonic Synthesizer.

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.

Aparillo is an advanced 16 voice FM synth tailored for complex sound structures , majestic motions, moving and evolving soundscapes and atmospheres that are perfect for film, TV or games.

Each of the 2 oscillators offers a selection of 5 waveforms: sawtooth and pulse waves are here, along with noise, triple saw and triple FM waves. There's also an additional sub-oscillator strapped into the master section for added oomph.

Cyclop is a monophonic synthesizer. It does one thing very well: delivering cutting-edge digital madness at the low end of the frequency spectrum.

Dandy is a sampler/synthesizer for iPhone inspired by Dandy Desmonds composition “Magnetic Loops for 15 Tape Decks” from 1938, which is one of the earliest known works of electroacoustic music.

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

Chiptunes Pro lets you make retro music the way it should be made - with chips. Build your circuit to lay down drum beats, basslines, and tunes.  No knowledge of electronics needed.

A Simple Ad-Free Piano-like Musical Keyboard. Easy to Play, Good Response and Small Application Size. Just Play the Instrument. The app doesn't use sampled real sounds but use FM synthesis. It sounds like piano though it's false.

TweakyBeat is a drum machine synth.

Make music in seconds. Share, remix and collaborate with music makers all over the world.

Jam Synth is a fully featured monophonic guitar synthesizer / multi FX for iOS.

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

4Waves Synth AUv3 is an easy to use synthesizer with a powerful sound.

Accelerometer Synthesizer and Bluetooth MIDI Controller.

RD4 - Groovebox is a music making app with virtual analog synthesizers, drum machines and effects.