One of the most commonly asked questions on the Facebook page for parents that I posted recently, (aside from how do I learn XYZ in tech realms to be ahead of the kids) is 'How do I limit my child's screen time?'.
I have found my most successful way...I use Bark. (When the phone limits are set, he actually gets himself to bed with no fuss.) But there are many other ways.
You've heard me preach all of August (click here for the column related post) that started it all, about the need to do this...now you can hear it from another source. One that I particularly like.
And if you have not visited or joined the Parenting in a Tech world Facebook page, you need to.
If not for anything but to learn what your kids know that you don't.
Don't wait until it's too late to take some kind of action, even if it's simply educating yourself...
Take it from me.