Author for both: Just me, @kiophen
Tool 1: Cohost Theme Customizer
What it does: It allows users to make their own custom color themes for cohost, and recolors every element on the site. It also allows for a custom background image.
Links to file and cohost post:
https://userstyles.world/style/7690/cohost-theme-customizer
https://cohost.org/kiophen/post/583603-cohost-theme-customi
Open source: Yes, it is free to alter and redistribute, the source is the file.
Does it require other software to operate?: Yes, the Stylus browser extension, or other userstyle extension.
Extra notes: I made this because cohost's dark-mode still makes the timeline background bright white. This is probably due to the fact that users can use custom css within posts and expect the background/text color styling to be consistent.
Tool 2: Cohost Tweaks
What it does: A compilation of several toggleable tweaks to the cohost layout, including a more space efficient layout for smaller resolutions, the ability to hide/shorten several post elements, the sidebar sticking to the screen, and others.
Links to file and cohost post:
https://userstyles.world/style/7657/cohost-tweaks
https://cohost.org/kiophen/post/568657-cohost-tweaks
Open source: Yes, same as above.
Does it require other software to operate?: Yes, the Stylus browser extension, or other userstyle extension.
Extra notes: I made this one because I always have my browser only take up half of a monitor. The default cohost css squishes the timeline while leaving a lot of extra horizontal empty space at smaller resolutions. Also, certain elements in posts were distracting to me, so I wanted to be able to turn them off.