I can understand where you're coming from. I have a four-, six-, and eight-year-old, and they are on their smart tablets, all the time. They're better at it than I am. We use it for teaching as well as fun.
As I said, when I was growing up, if I was going to get disciplined I'd probably get the wooden spoon. You're not allowed to do that now. We threaten to take away their smart phone and it's devastating for them. It's a good way to get them to listen to us.