--(BUSINESS WIRE)--T-Mobile US, Inc. (NYSE:TMUS): What:   T-Mobile US, Inc. (NYSE:TMUS) released its exclusive, hands-on First Impression videos of the hottest smartphones unveiled at Mobile World Congress in Barcelona today– the Samsung Galaxy S 6 edge and HTC One M9.   Who: The Un-carrier has made these one-of-a-kind videos available to anyone who wants to get a hands-on sneak peak at the new Samsung and HTC flagship devices.   When: Sunday, March 1st   Where: Online! See details and links be