T-Mobile has confirmed that iPhones on their network will be able to take advantage of the Wi-Fi calling feature that the US carrier has offered since 2007. Among all of the big announcements today about iOS 8 at WWDC 2014, Apple also had their customary slide of "all the rest" of the many other features small-medium-and-arguably-kind-of-large that they didn't have time to mention in the marathon two-hour event. Among them was Wi-Fi calling.
For the uninitiated, Wi-Fi calling works by latching onto your Wi-Fi networks to relay calls, offering you the consistency and reliability of Wi-Fi over the battery-sucking nature of the average cellular connection. Plus it can just plain sound better (and helps take a load off the cellular network).
The quiet addition of Wi-Fi calling to iOS 8 is something of a big deal, considering just how many iPhones there are and how many end up on the latest version of iOS. Presumably handled seamlessly and automatically on carriers that support it, Wi-Fi calling on iOS is one of those small changes from a user's perspective that could end up having a big impact on their experience with call quality, reliability, and battery life without even realizing it.