If anybody is curious about what that “GoG clone” is: gog-games.to

Does the F-Droid version not ship with Google AdMob?

Pixelix and PixelDroid both have a dark mode.

By the way, the official Pixelfed app on the Play Store seems to have Google AdMob integrated if you care about that kind of thing. I’d recommend installing Pixelix or PixelDroid from the official F-Droid repositories instead.