This is a simple login form in the widget. just install the plugin and add the login widget in the sidebar. Change some settings in the login widget panel and you are good to go. Add css as you prefer because the form structure is really very simple.
Upload widget_login to the /wp-content/plugins/ directory
Activate the plugin through the ‘Plugins’ menu in WordPress.
Download from wordpress.org.
The Serbo-Croatian Language translation file is provided by Web Hosting Hub