First it was Sprint, now it's T-Mobile's turn. After the HTC One for Sprint got updated to Android 4.3 earlier this month, the T-Mo version is following suit. As promised, the carrier has started to roll out the latest version of Android Jelly Bean, which brings improved low-light camera performance, new lock screen widgets, a quick settings panel in the notification bar, a battery charging percentage indicator and a bunch of bug fixes. As TmoNews points out, the update is a hefty 560.18MB, so you'll probably want to plug in and find a WiFi network before you get your download on.
HTC One (M8)