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.
using iPad with a USB-C hub and keeping it charged, USB audio interface
I'm using an iPad with USB-C and a "j5 create" powered USB hub. On USB I am using a Softstep controller set up for Quantiloop, a Behringer UMC404 audio/midi interface and occasionally a USB MIDI keyboard for use with Cubasis.
problem #1 - the powered hub does not charge the iPad. I don't think I can even use the powered hub to charge the iPad (by swapping cables) because the moment you unplug the hub from the iPad, power gets cut off to all the other devices which were plugged into USB.
problem #2 - the detection of the Behringer UMC on the iPad is really spotty. Here's what I've tried (various combinations and orders):
a) Plug in Behringer to external power (or don't, since it works off USB also)
b) Connect USB cable from hub to Behringer
c) Connect hub to iPad
And I cannot tell you the exact sequence which makes it work. I do know that I am going to wear out the USB-C jack on the iPad if I keep this up.
If I could charge it while it was attached to the hub normally that would solve much of the problem. As it is I can't just leave the thing on (which is desirable for spontaneity) without unplugging it once a day to recharge it. Then after unplugging the hub I have to do some crazy dance to get the UMC 404 recognized again.
I will also ask this over at the Behringer Forum of course!