Samsung gives Android 4.3 another try for AT&T's Samsung Galaxy S4 owners
Perfect for the BYOD crowd, Samsung KNOX offers you a secure container that locks in a number of enterprise applications like a browser, calendar, contacts list, and email. This allows you to keep your business applications separate from your everyday apps. Remember, business and pleasure don't mix.
If you missed out on the Android 4.3 update earlier this month, the update you get will weigh in at a hefty 727MB and can be on your phone via a Wi-Fi connection only. If you already installed Android 4.3, the update will be a 28MB clean-up to make sure that everyone is running on the new firmware version, I337UCUEMK2.
source: AT&T via AndroidCentral