FOSS, customizable, packed with features. It really can't get any better than this.

20Aug21. As of Big Sur 11.5.2 update, Dark Reader's functionality is broken. I've removed Dark Reader and reinstalled it. No Joy.

Good

Fonctionne très bien et j’apprécie beaucoup l’interface simple et claire.

Works perfectly so far in Firefox Nightly on Android.
*edit* Doesn't work on THIS site, even when enabled in settings and reload. (-1 star)

Great app, Ironically, the only website where it doesn't enable dark mode is the extensions site itself