Doesn’t do anything
I installed it, allowed it, enabled it but I don’t see any options on YouTube for this. Edit because of developer response. I would say not clearly because I have no pop over like you have in your screenshot, and am on an iPhone so there is no keyboard that pops up when watching a video. Looking at the permissions it has the YouTube sites listed as ask, but I have not been asked to allow the extension on any of them. I stand by my review that this extension doesn’t work, or if it does and I’m doing something wrong then the documentation needs work. Second edit: I played around with this some more and finally got it working. I had to go in and change ask to allow on all the sites because it did not ask me for permissions. Once I did that, the extension icon showed up in the address bar and I was able to use the extension. For someone who had never used a safari extension and barely uses safari on an iPhone before this was a bit of a struggle to figure out. For example I had no idea you could hit the Aa icon and open up all of safaris settings, including extensions. I will update my review to 3 stars, will make it 5 stars when the documentation issues get resolved.