Samsung is extending the rollout of the Android 4.4.2 KitKat update to the T-Mobile variant of the Galaxy S4 starting today (or rather, T-Mobile is beginning to push out the update after doing the necessary carrier certification stuff). Available both the over the air and through Samsung’s Kies program, the update will install on your device only if it’s on software version M919UVUEMK2, which was the final Android 4.3 build released by T-Mobile.
The KitKat build is M919UVUFNB4, and it brings features such as improved stability, camera shortcut on the lockscreen, reduced memory usage, wireless printing and NFC tap-to-pay support, new Google file manager that sources files from the cloud as well as local storage, improved Samsung keyboard in landscape mode, white status bar icons, and general performance and smoothness improvements. All of this is included in a 388 MB package, which you should download on a Wi-Fi connection to save on data costs.
As always, keep in mind that the update will take time to reach all devices, up to a week for some. But the wait is finally coming to an end, so that week should be pretty easy to bear, right?