What3words tools is a plugin for QGIS that enables the users to use what3words 3 word addresses in it.
The plugin is documentated here
This repository uses external repositories as submodules. Therefore in order to include the external repositories during cloning you should use the --recursive option:
git clone --recursive http://github.com/boundlessgeo/qgis-what3words-plugin.git
Also, to update the submodules whenever there are changes in the remote repositories one should do:
git submodule update --remote