Looking for an extension like TabCinema

Hello all,

I'm searching for an extension like [TabCinema](https://chrome.google.com/webstore/detail/fullscreen-anything/olcfgpmjldkkjdclidhcbonieibfhhdh) (similar to this on google chrome), basically, it make a video frame to fit inside a tab/window instead of the usual full-screen or F11. It used to work on firefox, but since the launch of WebExtensions, it has been discontinued like many.I also tried script for geasemonkey and so, which didn't really work on the desired websites.

Thanks in Advance