แƒแƒ› แƒ“แƒแƒ›แƒแƒขแƒ”แƒ‘แƒ”แƒ‘แƒ˜แƒก แƒ’แƒแƒ›แƒแƒกแƒแƒงแƒ”แƒœแƒ”แƒ‘แƒšแƒแƒ“ แƒฃแƒœแƒ“แƒ แƒฉแƒแƒ›แƒแƒขแƒ•แƒ˜แƒ แƒ—แƒแƒ— Firefox.

แƒจแƒ”แƒกแƒ•แƒšแƒ
แƒ“แƒแƒ›แƒแƒขแƒ”แƒ‘แƒ˜แƒก แƒฎแƒแƒขแƒฃแƒšแƒ

YouTube Enhancer ๐Ÿ’ป-แƒ˜แƒก แƒ›แƒ˜แƒ›แƒแƒฎแƒ˜แƒšแƒ•แƒ”แƒ‘แƒ˜

YouTube Enhancer ๐Ÿ’ป แƒแƒ•แƒขแƒแƒ แƒ˜ VampireChicken

4,4 แƒ•แƒแƒ แƒกแƒ™แƒ•แƒšแƒแƒ•แƒ˜ 5-แƒ“แƒแƒœ
5
40
4
9
3
3
2
2
1
3
แƒ’แƒแƒ›แƒแƒ”แƒฎแƒ›แƒแƒฃแƒ แƒ VampireChicken

แƒจแƒ”แƒ›แƒ›แƒฃแƒจแƒแƒ•แƒ”แƒ‘แƒšแƒ˜แƒก แƒžแƒแƒกแƒฃแƒฎแƒ˜

แƒ—แƒแƒ แƒ˜แƒฆแƒ˜ 2 แƒฌแƒšแƒ˜แƒก แƒฌแƒ˜แƒœ
YouTube has a "theater mode" already, maybe I don't understand what you mean by Theater Mode.
edit: Alright I understand what you mean now.
edit 2: Version 1.12.0 includes "Automatic theater mode" feature