Full disclosure: I posted the app (back then version 1.0) on HN a few months ago. It haven't had much attention so I changed quite a bit about how it works (1.0: website based channels => 2.0 topic based channels connected to multiple websites). I'm aware that browser extensions are still not that attractive. Because of this and because how the 2.0 version works, I'm working on a site-integratable version (like Disqus) for single channels. The difference to Disqus is that the channels can be integrated into multiple sites and therefor form a connection between those sites.
The whole thing is still very early and I would be glad to hear some thoughts on this or what use cases you come up with.
Btw the backend is written in Elixir/Phoenix which is just a blast and you should try it out if you're a web developer :-)