Hide Squad Chat v1.0.0
The chat bar in squad mode takes up a huge amount of screen space, and Twitch does not give you a way to remove the bar itself; you can only hide the chat text. This add-on gives you a more immersive viewing experience by hiding the chat bar.
Note: the add-on asks you for permission for "all of your data on twitch.tv." This is because the WebExtension permission to modify a page's appearance requires this privilege. The add-on doesn't gather any data at all; you can view the source code to see that it just inserts two lines into the inline stylesheet.