Twitch chat overlay v1.4.2
How did you live without it? ^_^
This extension for Twitch places a transparent chat over the video when viewing in theatre or fullscreen mode.
You can move it using the arrow icon at the top-right corner, or resize it by dragging the bottom-left corner.
In the settings panel (located in bottom bar of the video) you can toggle it on/off, change the font size or opacity of the chat.