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.
Official documentation for audio dev on iOS/macOS?
After not doing hardly any serious work on Apple platforms for the past 6–7 years, I thought I'd try my hands at some audio applications. But I'm having some trouble finding comprehensive and up-to-date documentation.
There used to be reasonably decent guides for the various tools and subsystems, but I can't find anything more than really terse references and the occasional specialised article on things like porting code to Apple Silicon or debugging out-of-process audio units.
The old guides are still available in the archive, but they haven't been updated since about when I last worked on mac dev! I'm kind of hoping not having to start from the old guides and work my way through ADC videos year-by-year to see what has changed.
Any pointers to good up-to-date reference materials will be greatly appreciated! (Official docs, books, blogs etc.)