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.
U need VOLT Synth │ Deep Review and Developer Interview - haQ attaQ 284
Numerical Audio's Expressive VOLT synthesizer is not just for Roli Seaboard or MPE MIDI keyboard players. This synthesizer sounds amazingly good and works just as well without an expensive MIDI controller. This very deep guide and review of VOLT synth also includes interview-bits with Kai Aras, the developer of Volt and hear him talk about the design choices he made when making Volt and why.