I get a "Secure Connection Failed" on Firefox/Chrome when trying to access the userium.com website: SSL received a record that exceeded the maximum permissible length. (Error code: ssl_error_rx_record_too_long)
It's no longer live on that domain. I should have maybe titled my post 'post-mortem of a side project'? :)
The checklist is nowadays here: https://stayintech.com/info/UX and the Wayback machine holds a copy of the old website.