T-Mobile has started alerting customers that it will retire its app for Windows phones soon. In a message in the app itself, T-Mobile says it will no longer be supported starting on August 25. Instead, the company points users toward its website for managing their accounts going forward.
From the message:
Thanks for being an awesome T-Mobile customer! We're always finding new ways to provide you with the best experience possible. Unfortunately, our Windows app will no longer be supported beginning 8/25/2017. Moving forward, you'll be able to manage your account at My.T-Mobile.com.
The move is curious, given that the T-Mobile app received a complete visual overhaul for Windows phones only around 10 months ago. Given the state of Microsoft's mobile efforts, however, it's not too surprising to see another company decide to retire its app. T-Mobile itself stopped selling the Alcatel Idol 4S in April, which was the last remaining Windows phone on sale at the carrier.
In any case, if you still happen to be using a Windows phone device on T-Mobile, you'll be stuck with using the carrier's mobile website as of August 25.
Thanks to Peter M. for the tip!