Does exactly what it says. :)

grate

It's cool but I can't open links from browser to app anymore, nor does it actually add any domains to the whitelist when I try to allow them to bypass.

Doesn't ublock origin do the same with the filter list "Block Outsider Intrusion into LAN" enabled?

Brilliant and enlightening little project. Foolish that people take stars away for not fulfilling their specific use cases. Don't ding it, just leave your gripes in the comments. This deserves five stars.

Good Project. Needs persistent settings. Gear Icon not available.

Thank you, ACK-J - this little extension works well. However, I've only rated it 3 stars because sometimes it proves to be a somewhat counter-productive annoyance. This plugin really, really needs a "whitelisting" option. For example, I can't log in and use box(dot)com and a couple of other sites/services that I use to backup my files online, unless I remember to temporarily disable 'Port Authority'. Please add a whitelisting option - that will make it a fully 5 star extension.