After LG G Flex 2 Android 5.1.1 update rollout in South Korea, the same update is now available for the Sprint USA variant of second generation of Flex smartphone by LG.
The new update brings the version number as LS996ZV6 and it's available for download via Over the Air[OTA]. Until now only a limited number of handsets are running on Android 5.1.1 Lollipop.
The Android 5.1.1 Lollipop doesn't bring any of the new features, instead it brings major bug fixes and improvements over Android 5.1 Lollipop.
If you own Sprint LG G Flex 2 in United States, then directly head to Settings > About Phone and then tap on Software update. You should be connected to WiFi for this minor update but any form of new software update is welcomed.