Utkarsh Kukreti

This plugin enables embedding of multiple stylesheets and javascript files on a per-post basis.
Multiple file names should be separated by a ‘,’. Extra whitespace after and before a ‘,’ are automatically ignored.
Relative paths to files are automatically prefixed by the /css or /js. These settings can be customized by editing values of the variables $css_folder and $js_folder in the plugin file.
Absolute paths are directly hotlinked.

Include Custom Files

Enables embedding of multiple stylesheets and javascript files on a per-post basis.

Samir Manjiyani

Mohammed Salman Khan

Add your custom CSS or javascript/jquery using “Custom WP CSS & JS” plugin to any theme without creating any extra CSS or JS files.
Benefits of Plugin 
* Easy to use. 
* Option to select placement (header or footer) to insert your custom JS. 
* Built with Syntax Code Highlighter. 
* Option to add custom CSS for WP Dashboard.
For Syntax Code Highlighter credits goes to <a href="https://codemirror.net/5/" rel="nofollow ugc">codemirror.net</a>

Custom WP CSS & JS

otimo

A lightweight plugin to add custom CSS, JS/Javascript to any theme. This plugin also gives you an ability to insert JS in header or footer.

Include Custom Files vs Custom WP CSS & JS