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 StoreAudiobus is the app that makes the rest of your setup better.
Metronome app - but with specific needs - suggestions please...
I am looking for metronome app that can stay on top of other apps, but be transparent and perhaps be run as narrow bar along the top or bottom of the ipad screen...
I couldn't really find anything on a app store search so thought I'd ask the knowledgeable folks here 
Comments
I hear you, and have no sugestion.
Instead I will snare my current way to excersize:
iPhone run LoopyPro with different kind of loops, in different divide, easly controlled by launchpad mini mk3.
Also there is iPad Pro for other sound source and additional synchronizuj beats.
If needed I can stop loops in LoopyPro and enable metronome sound, or prepare, record custom metronome.
If needed to use only one device then on iPad I use split screen.
Stage Manager?
https://support.apple.com/en-us/HT213405
Tick Metronome is a free auv3 metronome:
https://apps.apple.com/dk/app/tick-metronome/id1573209073?l=da
If you are using it in AUM, you can place it where you want it on the screen:
thanks all....just using an iPad for charts. Wanted a metronome to run without the need for a hosting app... background clicks are fine for at home in rehearsal, but not on sage...hence the need for one with lights I can force to stay onto.
Going to get a small battery operated digital (hardware) one. Thanks for the suggestions though.