Video Flipper v3.4
This extension creates two webpage context menu buttons that enable you to horizontally and vertically flip a streaming YouTube or DailyMotion video.
Right-click anywhere on the streaming video page to get the context menu options.
If you are using Youtube and right-click over the video, you have to right-click twice and the options will appear on the second click.
If you resize, maximize or change resolution of your YouTube video stream then you may have to wait a maximum of one second until the flipping settings are reapplied.