John Mann

This is used to change the header image, background color, and header link on the login page. 
Simple customization for the login page to make it more personalized.
<ol>
<li>Customize login header image</li>
<li>Customize link for that image.</li>
<li>Customize background color</li>
<li>Customize link colors and hover colors on login page.</li>
</ol>
Features: Uses new Color Picker, is localizable, uses media picker for images.

LotekMedia Custom Login

This is a plug-in to do some basic customization to the login page.

Harish Chouhan

Themeist Co

Custom Login Logo lets you replace the default WordPress login logo with your own — no need to touch code or upload files via FTP.
Just activate the plugin and use the built-in media uploader on the settings page to upload your custom login logo. It’s quick, simple, and works with most themes.
This plugin is perfect for branding client sites, personalising the login screen, or maintaining a consistent visual identity.
Features: 
– Upload your custom logo using the built-in WordPress media uploader 
– No need for FTP or coding 
– Works with most themes and setups 
– Retina/high-DPI image compatible 
– Lightweight and fast
If you find this plugin useful, please consider leaving a 5-star review on WordPress.org.

Custom Login Logo – Easily Add a Logo to Your WordPress Login Page

Easily add a custom logo to your WordPress login page using the built-in media uploader.

LotekMedia Custom Login vs Custom Login Logo – Easily Add a Logo to Your WordPress Login Page