This may be politically incorrect but I think parents should be able to take a page out of the Asian parents handbook and corporally punish their kids. I find a certain amount of fear in very specific cases works to get kids to focus initially until it becomes a part of their daily routine.
Much more effective would be to follow the Asian method of channeling that energy into something requiring a lot of practice and focus, like martial arts or an instrument, and bonus points if it looks good on a college application.
(If they don’t like the current thing you’re focusing them on though, consider switching lest they dislike you for the rest of their lives.)
Alternatively they could just take away the phone. Unless we're talking late teens (by which point you've hopefully imparted some self control on your kids) the kids are going to lack the ability to get their own phone.
