This property editor allows you to save any Umbraco page to a file on your web server.
One use for that is to allow CMS users to store pages to static files (such as for a 500 error page).
The GitHub repository has more details: https://github.com/rhythmagency/render-page-to-file
To install, first download the main ZIP file you see below. Then, log in to Umbraco and click "Install local package" (under the "Packages" node in the "Developer" section). Follow the instructions (you'll need the ZIP fie you downloaded).
Note that there was a bug in a previous version of Umbraco relating to routes for API controllers, so this property editor may not work in some older versions of Umbraco 7. It was developed using Umbraco 7.2.4, so definitely works with that.