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.
Free germs / prompts (if you can write the rest of the song)
Not only do I need somewhere to put them, but I collect so many that they will surely outlive me and thus if anyone gets a nudge towards something from any of the following feel entirely free to help yourself. By the same token, if you wish to share your own as you come across them, please do so.