marcucci

This is a very simple plugin that will check to see if a visitor is logged in before allowed your WordPress site to be displayed. 
If they are not it will display the login page of your site. It will also add text on the login page to explain that the site 
required all visitors to login.

Password Protect Plugin for WordPress

Force all visitors to login before accessing your wordpress site and add a message on the login screen explaining that login is required.

gilbarbara

Once activated and configured, this plugin will require users to fill selected fields before publishing posts, page, custom post types / custom fields.

Requird

Require users to fill selected fields before posting.

Password Protect Plugin for WordPress vs Requird