My kids are still too young (not even 5 yet) but we’ve decided it’ll be largely up to their peers. They won’t be first, but we aren’t setting up an arbitrary age. We have been working on their relationship with screens and we just have to hope we do a good enough job. Once they have them we’ll undoubtedly limit the hours per day/week and I’ll put some restrictions on what they can do with them, but they’re always used to “daddy tv” (my server) so I’m less worried about the specifics and more focused on keeping the relationship healthy and transparent with us.

Edit: that second phone concept someone talked about here is excellent. I might borrow that.