Source: http://lifehacker.com/5913671/mediaplus-enables-total-control-of-flash-and-html5-video
Chrome/Firefox: There's no shortage of browser extensions that help you download Flash or HTML5 video, but few give you the myriad of options available from MediaPlus.
Once you enable the extension on a page containing a video element, rolling your mouse over the video will reveal a toolbar. From here, you can download the video, move it around the page, blow it up fullscreen, pop it out into its own window, and even dim the surrounding page elements for easier viewing. Most of these options are available on their own in separate extensions, but MediaPlus saves you time by combining them into one package.
Media Plus for Chrome | Chrome Web Store via Ghacks
Media Plus for Firefox | Firefox Add-Ons via Ghacks