The Firefox version makes using this thing so annoying. It's great under Chrome but for some reason it slows down load times so much it's impossible to use with Firefox.
I mean, it's a great idea and when it works it works well, but if I wanted to wait 5 seconds for each page to load I'd stop paying for my high speed cable connection. I gave up on Chrome after the latest update and wanted to move all my plugins over to Firefox. The is the only one that caused enough hassle that I had to give it up. Too bad I got so used to it under Chrome.
The best looking dark mode for Firefox, however as mentioned by others, would love to be able to set a time for it to automatically turn on/off, and also it still has some performance issues - it would slow down pages or even the whole browser