As someone who came from Discord, I have always loved Vencord. It is a popular client mod that adds many quality-of-life features not found in the normal app, but no such thing existed for Slack in a way that did not feel full of jank.
So I decided to make my own. Packed with features I have long needed (as well as a few requests from friends). It has been quite the delight to build and make silly workarounds for Slack, and I hope you find this interesting and/or useful if you choose to try it yourself :D