T-Mobile US makes a big deal out of DIGITS

Disruptive US operator T-Mobile is rolling out its DIGITS mobile phone number portability initiative to all customers following a five-month beta.
At its core DIGITS seems to build on a number of similar initiatives tried out in recent years, the difference being this one is provided by an operator rather than an OTT like Google. Calls to your mobile number can now be picked up by other connected devices, presumably by routing the call though some kind of VoIP interface.
The other headline featu