Keybase is an encrypted chat, storage, encryption key directory, and more with clients for most operating systems including Android, iPad and iPhone. Additionally it allows people to create teams with admins, use git, send and store XLM (Stella) and create a web of trust to verify peoples identities.
To install Keybase on Kubuntu, open Konsole and type,
curl --remote-name https://prerelease.keybase.io/keybase_amd64.deb sudo apt install ./keybase_amd64.deb run_keybase
If you do not have curl installed you can install it by typing,
sudo apt install curl