AT&T Samsung Galaxy S4 is updated to Android 4.4.4 with Knox 2.0 in tow1
According to the changelist, the update adds a number of apps including Keeper, Mail, Live, Uber, Remote Support and Device Help. Before the update arrives, AT&T suggests that you back up your files to a microSD card, or use Samsung Kies to achieve the same task.
To save your precious data, AT&T recommends that you have a Wi-Fi connection when you download and install the update. And make sure that your battery is at least 50% charged. For those who keep score, the update weighs in between 392MB and 488MB.
source: AT&T via AndroidCentral