Redirects users to the previous url after login ( and logout ) by adding a redirection parameter to the links.
The plugin adds the 'redirect_to' parameter to all login and logout links in front-end. The value is the URL of the current site. Thus you're redirected to that site after login respectively logout. But if a link contains already a 'redirect_to' parameter, the plugin doesn't change it.
The Plugin affects only the links in front-end. These in wp-login.php and in admin back-end aren't touched.