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.
Join the dark side
This won't be a revolution for many but possibly it will turn useful to some:
Try to work with your devices at the lowest screen brightness setting possible will make your battery cycle much longer. Best results with brightness to absolute minimum. It can literally double your cycles and on the long run make the battery life a bit longer.
NB: at min brightness I can still see pretty well on the pad2 while on the 12" pro is a no go,