Upd:
Don`t install this addon! This addon doesnt provide source code repository and recently has changed owner! This may indicate new unknown owners will install viruses using this addon and steal your password! Be cautious!

Barely usable. Why do I need to shuffle manually though all categories of scripts to allow youtube load? this is ridiculous. Normal extensions like uMatrix or nuMatrix at least show what requests are blocked and it is easy to fix sites and apply whitelist rules.
This may be a cool extension for web developer geeks or paranoid maniacs who has many hours every day to fix sites with this not convenient GUI, but not for regular people.