I actually haven't even heard of keybase until now...
I'd like to try it out and see its functions for myself. As you can see, my negative trust has no clear reason (it is not yet resolved as of now) and you can see my appeal thread in my signature.
Edit: Upon research, I discovered that it was a signing tool that can be used to verify keys.
I'd just recently started using PGP encrypted messages and would like to use it on the go. Also, upon seeing this page:
https://keybase.io/jobs , I realized that they are planning to create a multiplatform version of this. Having an invite would really help me explore and integrate the PGP system.