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.
So... the Teenage Engineering OP-1 Field
How are we feeling about this thing? The OP-1 has always felt like an Apple-style status object, but this... this recalls overpriced debacles like 1982's infamous Apple Lisa in terms of what you're actually getting. For $2000, you could get an MPC Live II and a high-end synth, a 1TB iPad Pro and a suite of comparable software (if portability is the draw), a premium laptop with Ableton, or, a full-on DAWless set-up of decent synths and sequencers. I know people somehow love their OP-1s despite the first generation's $450 hike, but it really does feel like TE is a bit over its skis here.