iOS Musician Apps (580) Supported Technologies is Audio Unit (AU)

ChowKick is a kick drum synthesizer based on creative physical modelling of old drum machine circuits. The synth contains
useful parameters for adjusting the tone and fundamental frequency of the synthesized kick drum.

Spatializer is a great choice if you want to widen your sounds.

FabFilter Pro-C 2 is a compressor plug-in with a side chain options and a program-dependent compression styles.

So what is a midi echo? It is similar to the audio echo effect where copies of the original audio are repeated at regular time intervals but with some form of change (e.g. quieter). But unlike audio, midi is digital in nature (low resolution 8 bit mostly) and focused around the midi note on & off message used to control synths etc.

Polythemus AUv3 Midi was created for five main uses: сreating a polyphonic synth from individual monophonic synths, stacking different or similar synths that play alternatively for variation, interesting variations in timbre & rhythms by having multiple synths driven with a sequencer (e.g. Quantum) or arpeggiator, work outside IOS on hardware synths, voice allocation of externally hosted software vst(e.g. Logic or Ableton Live) using mac osx IDAM for direct device to mac midi.

Photon AU - Midi Recorder with Pad playback & Groove. Record your midi performances using this audio unit in your DAW then save/export them as standard midi files via email or directly to other apps.

Standalone and AUv3 iOS 80's synthesizer instrument.

A highly tweakable stereo delay AudioUnit effect, suitable for everything from clean digital delays to filthy dub echoes, flangers and broken cassette tapes.

High quality real time reverb AudioUnit effect, for everything between small rooms, resonators, and infinitely large spaces.

Ratshack Reverb is a detailed model of that classic of classics, the Realistic Electronic Reverb. Now, you can have the sound of everyone's first analog delay unit, without ever having to change batteries!

Make beats easily in landscape or portrait, your choice.

Respiro Wind-Synth for iOS is a free standalone app (IAA) and AUv3 plugin synthesizer giving you access to six fully functional wind instruments for your device.

Song Memo is the easiest way to take notes of your song ideas. The chord keyboard of Song Memo allows you to write chord progressions more quickly. Chords are automatically detected while you are taking a note.

Tape Cassette 2 is an audio plugin that emulates the warmth, noise and character of old tape cassettes. Following up from our well received Tape Cassette 1, we’ve updated the plugin with a sleek interface and more changes under the hood too.

Xequence AU | Pads is an expressive and fully editable (drum) pad surface for use inside AU (Audio Unit) hosts. It features the same, widely acclaimed pad editor that users of Xequence, our advanced MIDI workstation, have grown to love.

SynthJacker is an autosampler for iOS. It automatically plays back a MIDI sequence with the notes and velocities you specify, and records the results into an audio file. It then slices the audio into individual sample files, ready to import into an iOS sampler app of your choice.

Warm Distortion is Audio Unit effect app that creates nice distortion sound.

AUv3 Midi sequence generator which generates musical evolving sequences  that you can further automate or modulate via midi.

LRC7 is a seven-band EQ. It includes low shelf, high shelf, parametric peak/cut, notch, and various Butterworth low-pass and high-pass filters.

NeSi xTrem is a stereo-stereo tremolo effect that uses FM based LFO's and includes VCA and low-pass gate based modulation of the audio signal volume.