Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.Download on the App Store
Audiobus is the app that makes the rest of your setup better.
Well-optimized, lightweight, stable, bread and butter AUv3 synths / effects
Long gone are the days of NanoStudio 1 where you were able to run 16 instances of a good-sounding, heavily optimized Eden synth on an iPhone 4, which had a tenth of the processing power and memory of modern hardware. Add to that 3 OK-sounding insert effects per channel.
So here's the question: What's your favourite AUv3 synth of which you can actually load, say, 20 instances, play a single note on all of them at once, and get no crackles at all (not even during app switching, etc.) with a reasonable buffer size (256 bytes)?
Also welcome: lightweight, good-sounding bread-and-butter effects (Delay, EQ, Saturation, Compressor).