Main website: https://hackersmacker.org
Chrome/Edge extension: https://chromewebstore.google.com/detail/hacker-smacker/lmcg... Safari extension: https://apps.apple.com/us/app/hacker-smacker/id1480749725 Firefox extension: https://addons.mozilla.org/en-US/firefox/addon/hacker-smacke...
The interesting part is friend-of-a-friend: if you friend someone who also uses Hacker Smacker, you'll see their friends and foes highlighted too. This lets you quickly scan long comment threads and find the good stuff based on people you trust.
I built this to learn how FoaF relationships work with Redis sets, then brought the same technique to NewsBlur's social layer. The backend is CoffeeScript/Node.js/Redis, and the extension works on Chrome, Edge, Firefox, and Safari.
Technically I wrote this back in 2011, but never built a proper auth system until now. So I've been using it for 15 years and it's been great. PG once saw it on my laptop (back when he was still moderating HN, in 2012) and remarked that it was neat.
Thanks to Mihai Parparita for help with the Chrome extension sandboxing and Greg Brockman for helping design the authentication system.
Source is on GitHub: https://github.com/samuelclay/hackersmacker
Directly inspired by Slashdot's friend/foe system, which I always wished HN had. Happy to answer questions!