Keybase

Encrypt

Decrypt

Sign

Verify

Message to verify

Using the Keybase command line app

keybase pgp verify -m "message"

With GPG or another PGP program

You may import from Keybase to GPG easily and then perform whatever cryptographic actions you want.

# using curl
curl https://keybase.io/[them]/key.asc | gpg --import

# using `keybase pgp pull` which
# imports to GPG key chain for you
keybase follow [them]
keybase pgp pull [them]