It doesn't look anything like what you see in the screenshot. This extension calls itself "Dark Mode" in the add-ons section, then calls itself "Lights Off - Free" in the addons manager, but in the toolbar it looks exactly like "Dark Reader" which is a more popular addon from a different creator.
I wanted dark websites, not shady extensions!

it is like a branch-version or some thing, but it solved lazy-component's out-of-rendering. so i will give it A 5 STARs.

It works perfectly on Android, and so far it seems to be lightweight.