An interesting read. We've indulged my own children a bit much on the smart phone/tablet front, and we always tried to balance that out by making it a requirement that they have extra-curricular activities. That's how we justify it to a certain extent by saying that they'll need a phone to be able to get ahold of us should problems arise at practice, etc., and if they don't do things, they don't need the phone.
I think it seems to be working, but it is a battle to occupy them with something other than Minecraft YouTube videos.