The package contains the add-in and a sample page.  Install the add-in into the NAV database like this.

For NAV 2013 R2 copy the add-in into the Role Tailored Add-in folder.  In NAV 2015 create a dedicated folder in the server Add-in folder and copy the add-in file there.  The server will deliver the add-in to the clients as needed.

More information can be found on Dynamics.is.