Sprint's Samsung Galaxy S4 gets KitKat starting tomorrow says leaked internal document
Sprint customers with the device should make sure that they have the current version of the OS running on their Galaxy S4, or else they could be in danger of missing the update. The current software version is L720VPUFNAE. To make sure that you're currently up to date, go to Home> Menu> Settings> About Device. An interesting note at the bottom of the memo reminds Sprint stores to update demo devices to the most current software version.
If you're a Sprint customer with the Samsung Galaxy S4, smile. Your update to Android 4.4 could come as soon as tomorrow.