T-Mobile US launched video calling on Samsung Galaxy S6 edge+ and Galaxy Note 5 devices for customers with an LTE connection.

“This isn’t another app,” CTO Neville Ray explained in a blog post, as video calling will work “right out-of-the-box from your smartphone’s dialler”.

On devices with the feature, customers will see a small camera icon appear next to contacts with devices able to receive video calls.

“We’re working with others so you can eventually enjoy built-in video calling across wireless networks,” Ray added.

T-Mobile video calls can be made “using data straight from your high-speed data bucket”  as well as over Wi-Fi.

“Like HD Voice calls, T-Mobile Video Calling moves seamlessly between LTE and Wi-Fi. And, if you move off LTE or Wi-Fi to a slower connection, your video call seamlessly switches over to a voice call,” Ray said.

Samsung’s Galaxy S6 and Galaxy S6 edge will have the feature next week and the operator plans on adding three more devices by the end of the year.

T-Mobile claims it now reaches over 290 million people with America’s “fastest 4G LTE network” and was the first to offer Wi-Fi calling, HD Voice on both LTE and Wi-Fi and VoLTE calling.

It also said it is the first and only operator in the US to offer ‘Advanced Messaging’ – “upgrading regular SMS with real-time chat and the ability to share photos and videos up to 10MB.”

According to CNET, number one US operator Verizon also offers a built-in video calling feature for some devices, including the Samsung Galaxy S6, Galaxy S6 Edge, Galaxy S6 Edge+ and Galaxy Note 5.

The report quoted T-Mobile spokesperson Stephenie Hanschka as saying that “it makes sense to build technology that customers have gotten used to – like real time chat and video – into the native calling experience.”

Earlier this week, T-Mobile US’ outspoken CEO John Legere took the unprecedented step of criticising a small fraction of his own customers for “stealing data” from the company.