QuickFlip

On YouTube, the extension doesn’t flip the scrollbar or stop working when you hit the fullscreen button. In this regard, Flipper performs much better.

This extension seems to be quite good at flipping the image horizontally (swapping the left and right sides). I found it useful to overcome the flip that occurs when displaying a page on some teleprompters. It does not appear to modify the page (unlike another extension I tried that turned some text into all-caps when it's flipped for some reason). I don't have a use for the vertical flip mode of this extension, but did notice that scrolling seemed to be impaired. I would expect scrolling to be reversed, but it did not do that. I would think it could record the scroll position, vertically flip all the content of the page, then scroll to the corresponding position (page length minus previous scroll position), but I'm sure there's more involved in it than that. Even though there is room for improvement, this extension met my needs.

worked for me on mostly all sites, Reddit, Google, even on Twitter with videos playing. Weirdly though it didn't work for Youtube, which was why I got it in the first place. I turned off all other extensions, but it still didn't work. But it did work on all other sites even with all my other extensions on. besides that, it does what it says. Just not on YouTube, at least for me. if that could be fixed, I would give 5 stars.