Great idea!
A killer feature imo would be to control app usage also on time based limit.

Have a custom group/list of apps with all games, yt and other timeburners and define a custom limit, like 1 hour for all those apps.
Whenever any of them is active the granted usage time is decreased until daily limit is reached and a pin is needed for further usage of those apps.

From my experience it is a big difference if parents tell the kids to stop burn time (meeeeh, stupid parents) than the device "itself" setting limits (oh, it's like that, gotta move on).