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.
Automate tempo changes?
I have been using the Clyphx plug-in for Ableton Live to get smooth tempo changes when I need them. For those who aren't familiar, Clyphx has a "RAMP BPM" feature that lets you set a target BPM and the number of the bars the transition should take and then takes over. It's slick!
So, my question: is there an iOS app that has a similar feature? Specifically I'd like to control a smooth tempo transition via a MIDI CC.