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.
Files folder song player app
Currently using Foobar2000. All I need is something that will provide a folder for the song folders and a dencent interface for song playing, time slider, next, previous, pause. That's about it. Foobar is ok but it lacks a couple of things that would make it better for me and seems to have way more options than I will ever need at the same time.