T-Mobile announced it will support Wi-Fi Calling on the iPhone with iOS 8, which was quietly introduced by Apple on Monday. This feature will allow T-Mobile customers to place calls and send messages even in areas of poor cellular service, as long as there’s a Wi-Fi network. T-Mobile has supported Wi-Fi Calling on various other smartphones since 2007. To use T-Mobile Wi-Fi Calling, users must only connect to a Wi-Fi network while the feature is turned on. This comes after a recent announcement that T-Mobile has launched voice-over-LTE on its network in Seattle, though the iPhone is not supported as of yet.