My son has had an old iPhone4 for a couple of years now, just to play games and take photos. It has never had a SIM card while he's had it so has never been used as a phone.
I'd like to put a SIM card it in but only if I can find a way to restrict its use so that he can't get online at all and can only use it to text or call a few key emergency contacts (as well as still playing the games/music and using the camera etc).
He has started to want a bit more independence and I'd feel better letting him walk to his friends and play around the village without me if he has a phone on him.
Any technical advice ??