You can put the tinfoil hats away boys...
It simply tells you how many 'users' are connected. Nothing about device names or such. The engineering/debug mode might be able to do that if you dig enough, but haven't seen it do so yet.
I'm guessing the 'crew connected' is for the likes of QF whose crew use wifi enabled tablets to take pax orders in J & F. Probably just a feature of the system that we don't use (yet)