You probably know that you shouldn't shoot vertical videos on your smartphone — but everyone does it anyway. This simple bookmarklet rotates the video window for you so you don't have to watch a tiny letterboxed version.
Once you add the bookmarklet to your bookmarks toolbar, you'll be able to just click it whenever you come across a vertical video on YouTube. It will instantly take away the black space as well as enlarge the video to make it easier to view.
It's pretty cool, and a quick fix for the ever-annoying vertical issue. Hit the link below to grab the bookmarklet — just drag and drop the button to your bookmarks toolbar..