It'll be in the iPhone Game Centre - Most people use either Android or iPhone nowadays. Blackberry is dead.

There will be a game that has the ability to chat too within that.

Took a quick look at Game Centre for iPhone. How it works (I'm an Androidfag).

You can 'Challenge' your Friends List to a game and write an optional message. - This will be it

You don't need a game per se. Just a group of friends on iPhone who have Game Centre.