The first I ran into it, it was basically a key server where you could associate your public key with social media "proof" -- someone who had access to the priv

The first I ran into it, it was basically a key server where you could associate your public key with social media "proof" -- someone who had access to the private key proved it by posting from this Twitter account, this Github user, this Reddit user, etc. It seems like the last year or two they've really been ramping up ways to actually _use_ those keys though. They do have a chat app, which I've used with coworkers, but only to share stuff we don't want to send over Slack. It seems like at least part of the issue they've got with the homepage is that their "core" product -- hosting a public key for someone -- isn't really very interesting compared to the satellite offerings.