Protect My Phone From Kids

I have a 7 year old son and unfortunately he's discovered my Android phone and loves to play games on it. Although I allow him to use the phone for a limited amount of time on car rides and other family trips, I was wondering if there was a way to prevent him from accessing sensitive and important information. Because last time he accidentally downloaded a bunch of apps and then deleted a couple of messages. I would like to limit his use to just a few games, the camera and that's about it.

Is there an app like this?