Re:The growing body of evidence that digital distraction is ...
by DavideNL on Monday January 08, 2018 @06:30PM
(#16101951)
There's some of that in iOS: "Settings -> Restrictions", which will be locked by a passcode.
It has a lot of options, but probably not enough (like restricting specific apps.) You can however set to allow only apps rated "4+ years, 6+, etc.
Time limitation is possible too, via "Settings -> Accessibility -> Guided Access".
Once upon a time, kids went to school without phones, so it is possible...