Opticalworm

This plugin is an easy way to add table of content to your post/page directly or as a widget. It will parser the content of your post/page for HTML headers and generate a list of links. 
This plugin will require some CSS understanding to match your site and the know how for adding custom fields in your post/page.
<h4>Features</h4>
<ul>
<li>Easy to style</li>
<li>Widget</li>
<li>Display table of content anywhere in your post/page content</li>
<li>Can set which html h1 to parse</li>
<li>Can set your own title</li>
</ul>
<a href="http://hashdefineelectronics.com/wordpress-table-of-content-plugin/" title="This is the Plugin page where more information can be found" rel="nofollow ugc">Plugin Page</a>

TableOfContent

This plugin is an easy way to add table of content to your post/page directly or as a widget.

Stefan Pejcic

plugins.club

This plugin will automatically create a Table of Contents (TOC) from all Heading tags present inside the content.
Simply add the widget or shortcode <code>[toc]</code> where you want the TOC to be shown.
No settings, just activate and add shortcode or widget.
You can use custom CSS to further customize the style of the TOC.
For more free WordPress plugins please visit <a href="https://plugins.club/" rel="nofollow ugc">plugins.club</a>.

Automatic TOC – Table of Contents

Display a Table of Contents (TOC) from all Headings on the page.

TableOfContent vs Automatic TOC – Table of Contents