It is very experimental. The problem is not all browsers support it and it has one big side effect: if you load another page, it will jump out of 'full screen' in normal mode. Since some of time now, almost all browsers have forbidden to do this using code (mostly because of those popups that used to annoy everyone). I'm doing some dirty tricks for the moment to somehow make it work, but I would strongly advice not to use of it as I can not guarantee with the next browser update it will still work.