I came here for an extension that uses the Fullscreen Web API so my Firefox URL bar would be hidden. This extension does exactly the same as the standard "fullscreen" titlebar button on macOS, thus for putting your page into fullscreen it is useless. The other features are gimmicky. Also, I don't see the need to have extension options on your website.
This can do much more than that. I can bring your video to full screen, or your selected image. Also, it works offline to change the options (no need to open my website).
If you have any questions or still need any help, you can contact me on this support form: https://www.stefanvd.net/support I am happy to help you.
