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.
Cheapest iOS options for loopy pro (second screen)
I am VERY new to iOS and don't know what to look for in specs for early models [edit of ipads or iphones]
I am looking for a second device purely for a second control screen and for loading synths to a midi keyboard auv3
Maybe some mini recording on the go, but nothing serious
Any recommendations for what to look for in both used ipads and iphones