QuitPorn: Block Adult Content & Custom Sites od Zizou Dev

QuitPorn blocks adult websites, keeps Safe Search on, and lets you block extra sites yourself.

What it does:

Blocks 8,000+ adult sites
Lets you add any other site to the blocklist
Turns on Safe Search for Google, Bing, DuckDuckGo, Yahoo, and Ecosia
Optional filter for sensitive content on X/Twitter that includes posts, replies, profiles & communities
Shows time spent on sites (saved on your device only)
When a blocked site is opened, you are redirected to a short educational article in the extension.
The add-on is completely free.