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.
SWAM Strings / Improvised Classical
Lol, this is like starting up an old car... but it gets going.
SWAM Cello and Double Bass. These two are my favorites. Lots of interesting parameters not available with GeoSWAM. Plus iSymphonic Classical Flute, Module Choirs and Pipa. Headphones make it work.