Both if possible, so inside the app (which maybe could be done by setting the focus in accessibility mode?), and then at the OS level (so while navigating the OS to select an app, text someone, check your settings, etc..). And then third option which I'm not sure would be even possible given security/permissions of other apps, and how other apps handle it, but navigating inside another app from a picture-in-picture (when it looks minimized on your phone/tablet) view of the current app

Awesome, thanks that should work!