T-Mobile has announced that it will be pushing out the Android 4.3 update to the Galaxy S4 starting today, upgrading the device to build number M919UVUEMK2. The 781 MB update will be rolling out between today and all the way through February 1, which is quite a long time to be waiting for any update, though thankfully T-Mobile itself suggests that those unwilling to wait can manually update via Kies.
The Android 4.3 update brings support for the Galaxy Gear, KNOX, performance improvements and better RAM management, new camera features and firmware, two new home screen modes, visual touches to the interface, and improvements to T-Mobile’s Visual Voicemail and ISIS apps. Your S4 will have to be on build M919UVUAMDL if you want to get the OTA update, though others, as mentioned above, will be able to do it manually via Kies, or by downloading the firmware from our firmware section.