Back in May a leak told us to expect a new line of own-brand Android smartphones from T-Mobile to land at some point this year. It would be called REVVL, and the first device in the series was going to be the REVVL T1. Today the existence of this upcoming handset was confirmed by T-Mobile itself, because someone working for the carrier uploaded the relevant support documents already, even if the REVVL isn't official yet. This gives us a pretty good idea of what to expect. Although the documents simply call the phone REVVL, every detail they reveal lines up perfectly with what we had heard...
Source: http://www.gsmarena.com/tmobile_revvl_t1_leaks_again_this_time_courtesy_of_the_carrier_itself-news-26600.php