If you do a lot of split screen redditing, you'll quickly find that the sidebar can be a nuisance. Well, this script makes that sidebar retractable.
It adds a FAB button to the right-hand side of the screen which allows you to hide or show the sidebar. It will add a cookie remembering the sidebar's last position so that you can browse the site without continually hiding it.
You can install the script by going to the script's page on GreasyFork.
As of version 0.4 you can toggle the sidebar by pressing "q".