How can I enable calling over Wifi for a T-Mobile based Moto X? T-Mobile allows for unlimited calling when I'm tethered over Wifi, on my old Blackberry Bold this was called "UMT" or something like that  (it would appear in the status bar).

Since I still have poor reception I rely on wifi calling to get signal in the basement of my house.

How can I enable this T-Mobile specific (and no it's not Skype) wifi calling to work over a standard Wifi connection?
The Moto X does not support T-Mobile's WiFi calling. Customer support reps have stated that this is because it is not a carrier branded device, meaning they have not modified the system ROM to add this feature:


  The Moto X does work on our network but because it is not a T-Mobile branded device we do not support WiFi Calling on it.


You'll either need to set up some other VoIP service or get a different phone that supports this.