Grown-ups around the world have spent the last year desperately trying to get kids to put down their phones. Worries about kids’ screen time are far from new (you could argue that they are nearly a century old), but in recent months, high-profile experts have raised the concern that social media use among young people is not just an annoying time suck but a bona fide public health crisis.
Rather than relying on parents to limit kids’ phone time (which, as many parents can attest, is sometimes easier said than done)...