allilevine

This plugin adds an options page (Settings > Login Screen) that allows you to customize the WordPress Login Screen (wp-login.php). You can:
<ul>
<li>Upload a custom logo (it will be resized to fit if necessary)</li>
<li>Choose a link color</li>
<li>Choose a link rollover color (defaults to a darker shade of the link color)</li>
<li>Choose a button color (defaults to a button version of the link color)</li>
</ul>
The plugin also links the new logo to your site URL.

Simple Login Screen Customizer

Good

Choose a logo and link color for the login screen.  The plugin will do the rest.

Nazmul Hossain Nihal

Using this plugin you can make changes on login screen of your WordPress site.It can detect your logo image size automatically.You can add logo to your login screen,change the color of the other elements of login page.It has a color picker so you don’t need to worry about color codes.
What you can do with this :
<ul>
<li>Change Login Logo</li>
<li>Add Favicon of login page</li>
<li>Change Logo Hover Text</li>
<li>Change Logo Url</li>
<li>Change Background Color</li>
<li>Change Login Form Background Color</li>
<li>Change Label Color</li>
<li>Change Input Text Color</li>
<li>Change Input Background Color</li>
<li>Add Custom CSS</li>
<li>Use Shortcodes</li>
</ul>

Login Screen Manager

Using Login Screen Manager in your Wordpress site you can easily customize your login screen.You can add your own logo to the login screen,change styl …

Simple Login Screen Customizer vs Login Screen Manager