It's driving me crazy... It does not respect sites already providing their own dark-mode and even configured that particular domains should be ignore by this add-on, it forced it's own dark-mode:
aaa.abc.at --> dark-mode YES

But does dark-mode also for bbb.abc.at! RRRrrr... does not respect sub domains? Bug? Feature?

Hello is this addon still alive? My addon not works ok, i can't load "client area" site. Developer is not contact back on any chanel...

Was great, but this add-on has just stopped working on service-now.com text fields. Use this every day to minimize eye strain so it's extremely frustrating. Oddly, the page first loads and the fields are all blacked out wonderfully, but then the page continues to load and the black background disappears but the text is still very light grey so it's damn near impossible to read anything.

blocks pics & vids on many websites as well, at most semii-functional

This is a very effective extension but it is not without some drawbacks. First, the lite version only allows 5 sites but the full trial is forced on you for several months. This means you have to manually uncheck it for every site you don't want it on. Second, it really eats resources. Third, bugs. A few months ago it was crashing tabs that didn't like an update. A couple of weeks ago an update introduced a memory leak which locked up my entire computer. It took several days to narrow down the source of the leak and yep, it was this addon.

If they make the full version opt-in so that you only get the five free 5 sites and the addon isn't eating all the system resources trying to change all the other tabs then great. Until then I'll avoid it.

Basic functionality works, but some websites become completely unreadable. Also, it doesn't really turn "off" correctly, and I have trouble getting it to ignore certain websites. For example, duckduckgo has a great built-in dark mode, which I always use. However, this app doesn't think I should use dark mode during the day and overrides my settings, even when ostensibly "off". Super annoying!!! No way to tell it to just ignore duckduckgo.

Barely better than the free ones, nothing that impressive, too expensive in my opinion when you know what you can get for free. Also doesn't let me try the lite version before having the trial, it feels like it's just meant to mess with people when the trial ends really.
Basically, there was an attempt to make something great, but it feels malicious and I hate that.

looks good, but slows down firefox until it's unusable because my CPU (i7-6600U) is utilized at 90-100%

Extension payante !!!

as many said slowed down and made it unusable on several web sites, I thought it was good on Facebook too until I got to my home computer and it was awful and it is a far better equipped computer... I'll wait for an update or a built-in solution. (on Facebook it turns all the emoji black)