We've been experimenting with a bunch of different ideas and features—most of them you can enable/disable in the extension's "options". We launched a Reddit-focused extension last month but this release embraces all of the social networks that we support.
I'll be writing up a blog post soon, particularly about how we use the WebExtension NativeMessaging API to communicate securely with the Keybase service.
http://lettergram.github.io/AnyCrypt/
I use it with a few friends, it isn't super secure (in the sense I store people's private key locally). The real issue I had was two fold:
1. You guys really didn't want me pulling the private key from your servers. Although it was possible, I had to decode all the work you guys did, which sucked.
2. It wasn't seemless, i.e. I had to do some right clicking.
The one benefit I see on my current method, is I can use any chat to communicate. I already use signal, have encrypted emails, etc. So what do I gain using this extension?
Sorry to hear about your troubles reversing the key infrastructure. I'm not involved in that part of Keybase, but if you'd like to discuss it further I can put you in touch with the right people if you PM me.
Regarding what you're gaining with the extension: Our goal with the extension is to improve workflows for Keybase power users, and generally make it a little more user friendly/convenient in some scenarios.
As to what you gain from using Keybase: It's a much more sophisticated product than Signal or encrypted emails. A core proposition is cross-verified social proofs. You can Keybase chat with shazow@twitter and have a strong guarantee that it's also shazow@hackernews. The way Keybase does key management and device provisioning is very cool too. And did I mention file storage and sharing? And more coming soon!
I installed the extension in my browser and now whenever I hit the "keybase chat" button I get the message "You need the Keybase app to send chat messages." The keybase desktop app obviously runs fine in the background.
Browser: Version 58.0.3029.110 Built on Ubuntu, running on Ubuntu 17.04 (64-bit)
Btw: Would you consider putting the Android app on F-Droid?
Also, is it Chrome or Chromium?
Feel free to message me directly on Keybase if you'd prefer: https://keybase.io/shazow
[Edit: In case anyone is curious, this has been resolved by restarting Chromium.]