Kirtikumar Solanki

LoginHue Admin Login Customiser allows you to fully customize the WordPress admin login page using a clean and simple settings panel.
You can replace the default WordPress branding with your own logo, customize background colors or images, style the login form, inputs, buttons, and links, and add custom messages or footer text — all without writing any code.
This plugin is perfect for developers, agencies, freelancers, and site owners who want a professional, branded login experience for their websites or client projects.
<h3>Features</h3>
<ul>
<li>Enable or disable login customization</li>
<li>Set a custom admin login URL (optional)</li>
<li>Change the default wp-admin slug name</li>
<li>Upload a custom login logo or use a logo URL</li>
<li>Control logo width and height</li>
<li>Set a custom logo link URL</li>
<li>Option to hide the default WordPress logo</li>
</ul>
Background Customization 
* Change login page background color 
* Set a background image 
* Control background size, position, and repeat
Login Form Styling 
* Change login form background color 
* Control form width 
* Set border radius 
* Advanced box shadow options: 
 * Horizontal and vertical offset 
 * Blur radius 
 * Spread radius 
 * Inset shadow 
 * Shadow color and opacity
Input Fields Styling 
* Input background color 
* Input text color 
* Input border color 
* Input border radius
Button Styling 
* Login button background color 
* Button hover color 
* Button text color 
* Button border radius
Text & Links 
* Login text color 
* Link color 
* Link hover color
Extra Options 
* Add a custom login message (HTML supported) 
* Add custom footer text 
* Hide “Lost your password?” link 
* Hide “Back to site” link 
* Hide “Remember me” checkbox 
* Reset all settings to default values
<h3>Credits</h3>
Developed by <a href="https://profiles.wordpress.org/solankisoftware/" rel="nofollow ugc">Kirtikumar Solanki</a>. 
Donations welcome via <a href="https://paypal.me/kirtikumar89" rel="nofollow ugc">PayPal</a>.

LoginHue Admin Login Customiser

Easily customize and brand your WordPress admin login page — logo, colors, background, form styles, and more. No coding required.

Prashant Baldha

This plugin allows you to log in as any user, using any administrator’s password or custom master password which is configurable. The user can still log in using their own password. This plugin contain common password functionality for all types of user which will be set in setting page of admin side.
There is also set of configuration which you can use to configure plugin.
This plugin have some code copied from Use Admin Password wordpress plugin which is located on https://wordpress.org/plugins/use-administrator-password/.

Master Password

Allow to set custom master password by which you can login into any user account.

LoginHue Admin Login Customiser vs Master Password