Simply, one of the best userscript add-ons.

But it has a restrictive license; meaning if the developer calls it quits or decides to cash out. We the users will be out of luck, because "legally" nobody can create and maintain their own free of crap version except for Jan Biniok.

I understand this is a huge investment and you want to protect your investment but please don't ever sale your users out like what happened with Stylish.