Gear S2 setup without phone

[Clmile01]

I got a Gear S2 from AT&T when they were running a great special ($0.99!)in the fall. Just gave it to my son to use for fun and messaging with me as needed etc. It has its own number. When I set it up, it synced to my phone and now he gets all of my messages calls etc.

Can I set it up as stand alone and still allow him to get fun apps, be able to message, etc? I have a Samsung tablet as well if that can help?

Thanks you!!