One of my favorite milestones of late is that Ian can play games on the iPhone by himself. Even just last month there were several games he liked but lacked the dexterity to manage on his own. So it led to a lot of frustration for both of us as he would micromanage our every click on the screen with fits of "No Mommy, there!" But now he just says, "Mommy I wanna play Thomas on Daddy's phone." and I'm all "Knock yourself out, kid."
I'm not sure what age you're supposed to be able to do certain things. I actually read a fascinating article this morning about when kids can recognize colors. But he kicks butt at the matching game! And he can navigate through the stories that it reads to him and knows which arrows do what and how to get back to the main menu. I know adults who can't do that.
I've heard some folks say that they don't want their children exposed to too much technology too soon, but I haven't seen a single negative aspect to it thus far. Since it's all he's ever known he doesn't know to be nervous about its repercussions and just enjoys matching tiles and reading books in the back seat.