Hey Ben,
Ah, that is a plugin and plugins needs to be installed via Extension Manager in Joomla. There are basically several types of apps on our app store,
Applications
These needs to be installed via the Applications section at the back end of EasySocial
Plugins
These needs to be installed via Joomla's Extension Manager
Templates
These needs to be installed via Joomla's Extension Manager
Modules
These needs to be installed via Joomla's Extension Manager
P/S: I have already installed the docker plugin for you and it will be accessible under the Plugins Manager in Joomla.