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.
In my studio DAW, I always automate a volume utility plugin (Fruity Balance, for those interested) instead of my mixer channel fader. That way I can keep my automation as is and use the fader when mixing a song. In AUM, I tried doing it with the built-in gain module, but that only drops the signal by 24db at the most. Are there any simple volume or amp apps that I could use for this? I could, of course, just use a compressor plugin or something with no compression active, but this seems overkill and would cost unnecessary CPU usage (I assume).