Simple, realitively easy to use once you figure out to use the "Block domain and all subdomain" setting. Works really well to block unwanted websites. Only thing holding me back from putting 5 stars is that it would be nice to have a password lock option to prevent unwanted changes to the block list.

Doesn't work for some reason, tried blocking youtube.com, facebook.com and reddit.com.

Edit:
I figured it out, when using the default rule (Block domain) it only applies to the second-level domain (youtube.com) but since many websites redirect to www (www.youtube.com) it stops working. Using the rule "Block domain & all subdomains" fixes this problem.

Tried to block youtube and twitch, it worked. However, when I tried blocking instagram, it doesn't. Dunno why...

Very much good, I easy block fakebook.com

Easy enough to use, added the websites I wanted to block, set to block in private tabs etc, closed Firefox, restarted, entered one blocked website address, it loaded fine, entered 2nd, it loaded fine, tried 3rd, same scenario, it just isn't blocking these websites.

I watch too much porn

Nice and simple, works great!

A simplistic Website Blocker. But I would love if it had an option to visit the blocked websites without having to deactivate the whole add on.

Would be better if it could actually block URLs rather than act as an internal redirect. If I wanted a redirect, that's what I would have searched for and installed.
*Update: Since the Dev is actively working to improve and add new features, I'll boost my original rating. I realize development is a process that takes time. I'll give it another try when I get some time to do so. Until then, good luck with the add-on.

Great, add websites in the add-on page. Save out to backup between computers. 9/10 still a few pages to block not working. Great app, well done. Supplemented with https://hostsfileeditor.com/ to add the addresses this program won't block. Now we have a free focus time-waster blocker. Thanks!

Works great, please add a icon for this please I have to manually go into my addons. I would appreciate a icon. I inserted the link, it works great with ease. Just needs a icon to play with

Thank you very much!