Reading about this: http://9to5mac.com/2015/06/10/t-mobile-ios-9-cellular-continuity-iphone-ipad-mac/ I see the Apple Watch is one of the toggles. Does this mean the watch now has phone capabilities away from the phone? Like if I left my phone at home and had my watch I could receive calls? If so, do I need to be connected to wifi? Or just with cell reception?