Samsung's best-selling Galaxy S3 smartphone has been spotted running the recently leaked Android 4.2.1 Jelly Bean ROM. A video has now surfaced on YouTube, which shows the Galaxy S3 running the Android 4.2.1 software.

The video is courtesy YouTube user Damian Kidd, who took the leaked ROM and flashed it on his Telstra-branded Galaxy S3 smartphone. The five-minute video showcases all the new features that the Android 4.2.1 Jelly Bean update will bring into its fold, including the much-touted lock- screen widget support.

Samsung took the wraps off its much-awaited Galaxy Note 8.0 tablet at the MWC, which will throw the gauntlet to the iPad mini; however, the Galaxy Note 8.0 runs on the older Android 4.1 Jelly Bean and not the latest Android 4.2 Jelly Bean software. The video courtesy of Damien Kidd gives users a peek into how the software upgrade will fare on Samsung devices.

The Android 4.2.1 upgrade brings with it several nifty features and tweaks to the user interface. The notification panel now has two new toggles — Hotspot Mode and Flight Mode — and users can see all the toggles with just a tap of a button.

The software upgrade also brings new voice commands. To illustrate, if a user has the camera app open, simply saying "cheese" or "smile" will prompt the app into action and the camera will snap a photo. Rumor has it that the ROM also brings memory management improvements, although Damian Kidd did not notice any difference. However, the leaked ROM is probably not the final software version.

The Android 4.2.1 update is speculated to hit the devices after the release of the Galaxy S4 smartphone from the Korean tech giant, so we can expect an April roll-out date for the upgrade.

Check out the Android 4.2.1 Jelly Bean software in action on the Galaxy S3 in the video below.