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.
Video: why you need 96 KHz sample rate to clearly record frequencies up to 20 KHz
Recently I am enjoying making some tutorial videos that explain questions about signal processing. I made this video explaining why higher than 48 KHz sample rates can sound considerably better to the ear.
It's long, heavy, and complicated; but it makes an argument that may make a difference for people who are serious about sound quality.