I spoke with a T-Mobile customer service rep today and was told that *ALL* iPhone models that can run iOS 8 will support Wi-Fi calling. I was even put on a "Brief hold" while she verified this. As an iPhone 4s user who sees no reason to upgrade to any of these new iPhones (they do the same thing as mine, just a bit faster), this makes me very very happy!
Looks like it's done incredibly cheap, look at that 1985 Timex watch display. And what are the dimensions? Because if it is bigger, thicker, and heavier than having credit cards in your wallet, what's the point?
iPhone is going to wipe this off the map.