By benlumley Password Protect Staging Plugin
Quickly and easily password protect a site to keep it from the prying eyes of google.
Enable, set a user and PW via WP admin and users will be prompted via HTTP AUTH for a user/pw before being able to view the frontend.
Aim of the plugin is to protect staging sites from the prying eyes of search engine robots, and to keep out anyone who might stumble across it accidentally.
This isn’t particularly secure – password is in the database.