Sprint announced the Flash back in November last year, when it launched with Android 4.0. Well, it's finally getting an update to Android 4.1... 9 months later. Ugh. The new software version is N9100V1.0.0B15. Improvements aside from things like Google Now and expandable notifications include enhancements to the camera app, which now includes blink detection, flash mode toggle, an EXIF data menu, and a detailed settings menu.
You can start checking for the update on your device now, though the rollout may be staged over the next week or two.