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.
Not sure if this is compatible with Audiobus, but I came across a new karaoke app called OkeMaker which allows you to create your own karaoke videos. I know there are a bunch of karaoke apps out there, but I loved that this one allows you to create your own lyrics and then sync them to the music. If you're into karaoke apps, definitely go check it out! I have no personal association with it BTW.