This website is intended to check if the sslstrip plugin of Ettercap is working. This should be done every time something in the plugin or the required bundled component curl is changed.
It basically provides a POST form and a link placed on a non-SSL website targeting optionally SSL protected resources. If the everything works correctly, the attacked victim should end up in passing data of the form via a non-SSL connection, hence Username and Password should be displayed in Ettercap.
This is a test link to a SSL website: SSL Link