By now, Nexus 6 fans are all a-gaga about the latest buzz in town: WiFi calling. And perhaps a little dazed. As is clear by now, the wireless network T-Mobile is already a bit late on its promise to have the distinctive service delivered to its deserving clientele early this year.

Still this killer feature could be any Nexus 6 user's best friend. In fact, as users from the competition may have been wondering by now, this is one must-have they dare not miss. But what is it really?

Recent report from TmoNews, foremost purveyor of T-Mobile news, revealed that a bug has kept the software update from rolling the Wifi calling feature. More specifically the brief cited T-Mobile product expert Des Smith who has given notice via Twitter confirming the 7-10 day timeframe needed to get the update rolling.

Though, as updates usually go, it could take longer than what Smith prescribed. Still this could be the time when batting an eyelid could be a bad habit. For Nexus 6 fans, that is.

To tell you what it is, we start by showing you what it's not.

First stop. It's not an app.

That means any enterprising Tom, Dick and Harry can not just download WiFi calling to avail of it. At least not yet in this rapidly-changing Android universe.  

Wi-Fi calling website explains:

"Wi-Fi Calling uses Wi-Fi to provide better mobile phone coverage. It is based on a Smart Wi-Fi Application from Kineto Wireless that is pre-loaded onto your smartphone."

And proceed to give a list of all the smartphones that could get it.

What does it do?

Simple. It allows you to send SMS, call and other mobile services done like you would by utilizing a WiFi network. Yes emphasize that: WiFi network. No need of cellular data. 

So with this you won't be needing a cellular coverage. As long as there is Wi-Fi you're good to go.

How will you know it's operating in your phone? Answer: a blue "talk" bubble appears. 

Now, with that said. You can imagine just how much cheaper your bill will be. If you are not excited about WiFi calling, perhaps it's the best reason to own a Nexus 6 right now.