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.