Rated 2 out of 5 stars

This extension does not provide full screen. Yes, it removes the navigation toolbar. But all the controls at the bottom are still visible and at Youtube they are shown in a distorted very large size. Plus, mousing over the top of screen does NOT return the navigation toolbar. It returned my tabs only ...not the navigation bar nor the menu bar. I had to close and reopen SeaMonkey to get the toolbars back. This is on Windows 8.0 Pro.

Full screen means NOTHING is seen except the video. Even the mouse pointer is hidden. The video I tried was playing with side bars in the so called full screen! On Fx 41 and Pale Moon it plays in true full screen and no side bars. Of course, it plays using Flash on those browsers.

There is no way to get SeaMonkey to play videos in full screen. I installed the extension I use on Fx and Pale Moon to force Youtube to play in Flash Player and even then I could not get SeaMonkey to play a video full screen. It still showed the controls at the bottom (but not at the top and no black bars on the sides). Fx and Pale Moon used to do that but that was several versions back.

Maybe some day SeaMonkey will be able to do full screen videos so I can use it for TWCTV but as it is now another browser has to be used for videos.

If you don't have true full screen with this extension then it means you must have something installed on your system that conflicts with it - possibly another extension, a third-party theme or custom script or style. There are so many different combinations of these out there that it's possible some of them will clash and it's almost impossible to test them all. I'd suggest trying in a clean profile.

And BTW, YouTube full screen works very well in SeaMonkey with this extension, which means no navigation bars anywhere, no video controls and no mouse pointer, just the video and nothing else!