Continue the conversation, wherever you are. AT&T Real-Time Text (RTT) helps AT&T customers with disabilities communicate over the wireless network as an alternative to TTY (TeleTYpewriter). RTT uses a free-flowing mix of text and voice conversation, so as quickly as characters are typed on the sending device, they are displayed on the receiving device. RTT is a separate service from traditional text messaging (SMS). –Great for everyday communication –Supports 711 and 911 calls –Eliminates the need to connect to mobile TTY devices –Works on the AT&T cellular network and over Wi-Fi Calling –Offers a more natural, conversational flow compared to TTY and relay service for persons who are deaf, hard-of-hearing, or have speech disabilities –Supports simultaneous text and speech on RTT-to-RTT calls –Automatically imports contacts from your phone –Works on iPhone iOS 9.0 (iPhones & iPads) and up; [1]Data and voice rates may apply for app download & usage.