It was a best ad-blocking add-on I ever used. But it was before the new UI with a new approach for using this add-on were added. It's not a useful add-on for now. Now can't create or edit blocking rules in an easy way, you must go deeper into the settings. But the most annoying thing - it's not possible to use "Block element" just like before. It works randomly, it could work on some sites, but it couldn't work on other ones and I can't understand why. I'm going to remove this add-on and have a look at another one. Very disappointed.