It's been just a few days since the FCC granted AT&T's waiver request that allowed the company to finally turn on its WiFi calling feature, and now WiFi calling is officially live. AT&T confirmed as much in a blog on its site, and it works just as you'd expect. Right now, only an iPhone with iOS 9 will work, but as long as you're on a WiFi connection, your phone will route calls through that connection if you cellular signal is bad. It's a feature that T-Mobile and Sprint have provided for a while now, but regardless it's good news for a select group of customers on the USA's second-biggest wireless network. We're hoping that other phones besides the iPhone soon, but if you are among that select group of compatible customers, you can give it a try now.