AT&T has belatedly brought its wifi calling service to Android, with the LG G4 being the only model currently supported.

The American telco launched wifi calling for iPhone 6 postpaid customers back in October last year, and has just gotten around to introducing compatibility with Android device for the first time, on an albeit severely limited number of devices.

While, until now, AT&T’s wifi calling service has only been available on iPhone, the carrier said additional Android devices, including Samsung and HTC devices, “soon”. According to Bill Smith, AT&T’s President for Network Operations, wifi calling on its network allows for fee-free international calling, further minimising roaming fees as the industry, particularly Europe, moves away from a cash-rich but negatively perceived roaming revenue model.

“Wi-Fi calls are billed based on the number you are calling or messaging,” he said on the AT&T blog. “It’s the same no matter where you’re connecting to Wi-Fi. For instance, making a call on your U.S. number to another U.S. number is free of charge, even if you are overseas.”

In order to launch wifi calling in the first instance, AT&T had a length case ongoing with the FCC resulting in the regulator granting a temporary waiver over a specific element relating to text telephony (TTY) support. The FCC feared that wifi calling’s incompatibility with TTY would be an inclusivity barrier for the hard-of-hearing.

While the launch of wifi calling for a few more AT&T customers, there is still a sizeable portion of its customers yet to be permitted access, as those with even the latest models of most Android handsets still have an unspecified wait on their hands.