I imagine this could be set up on the operating system side. All the apps would receive is a go/no go signal, not fine coordinates
That would be a good start. I guess someone at Apple has already been brainstorming about it for a while. I still think geofencing is a poor bandaid to patch a problem we've created in the first place. Just like notification filtering rules, it's like liquor vendors referring you to addiction therapy.
Or maybe the schools just don't let kids bring phones in at all.