What is Sandstorm? See sandstorm.io
Sandstorm is a self-hostable web productivity suite. It's implemented as a security-hardened web app package manager.
Sandstorm lets you run your own server and install apps like EtherCalc, GitLab, Etherpad, Wekan, and more as easily as you'd install apps on your phone. Sandstorm handles login & access control, and can run any web app that runs on Linux, though some apps may need changes to work within the Sandstorm sandbox.
Sandstorm is very new and a lot of features have yet to be developed; however, many people are already using it for real work every day.