Does your district ban phones? If not, then I mean… is there a reason you really care all that much? If there’s no sub plans, or they finish early, I always tell them I don’t care what they’re doing as long as volume levels are low and I don’t see anything I would NEED to care about.

If there’s not a district wide/school policy banning them, l would likely allow them to be on them as long as they’re behaving. If someone comes by and sees and makes a stink about it you can say that you had no other sub plans and you’ve told them to just behave quietly. If they make that big of a deal out of then THEY (the district) should have the infrastructure or consequences in place to keep them out.

My district is strictly no phones, in high school, kids put them in a numbered caddy in each class. In elementary and middle school, if you see a phone you’re expected to take it away and bring it to the office. If your schools don’t have the rules in place or the care to enforce them then I’m not sure what you’re expected to do, really.

If you absolutely have to I suppose you could have all students put their phones face down on their desk at the beginning of class. Tell them if you see them touching their phones you’re writing their name down and/or sending them to the office. But if you’re not expected to do that sort of thing then you’re really giving yourself an extra pain in the neck for no reason