This plugin Adds Crazy Additional Password Protection and Security to your blog.
For more information and support, check out: http://www.wpsos.io/wordpress-plugin-htaccess-site-access-control/
Quickly and easily password protect a site to keep it from the prying eyes of google.
Lightweb Media Basic Authentication for protected your development WordPress site like .htpasswd
htaccess protect - Protect your wordpress login or admin pages with password.