Cresencio

This plugin will allow you to create a bootstrap accordion with default styles to any post, page or section with a default WordPress editor. After installing this plugin you will have a tiny button added to your editor that will help you generate the necessary shortcode.
Features:
<ol>
<li>Fully responsive</li>
<li>Easy to use. </li>
<li>Add any type of content to an accordion section.</li>
</ol>
<h3>Demo</h3>
For a demo of this plugin please the video at http://www.youtube.com/watch?v=HaqU1h1Okms

WordPress Accordion

Add a responsive accordion to your WordPress website with this easy to use accordion plugin.

Farhad Sakhaei

ParsMizban

DediData

WordPress + TinyMCE + Font Awesome + Bootstrap 
This plugin extends the buttons on the Visual Editor toolbar.
It includes 20 plugins for WordPress Editor (TinyMCE)
<ul>
<li>Insert Many Icons from Font Awesome Set easily, Change their Size or Border!</li>
<li>Support HTML Templates (We will add many pre-designed templates soon!)</li>
<li>Insert Table of Contents based on headings</li>
<li>Insert sample of codes, and colorize them</li>
<li>Insert emoticons</li>
<li>Change Text Colors and Back Colors</li>
<li>Great Context Menu</li>
<li>Print, Paste as Text, Find and Replace, Insert Media, Special Characters, Horizontal Line, Read More Tag, Page Break Tag, Anchor, DateTime</li>
<li>Support for creating and editing tables.</li>
<li>Search and Replace in the editor.</li>
<li>Show Blocks, Show Invisible Characters</li>
<li>Insert predefined styles and Clear Formatting</li>
<li>More options when inserting lists.</li>
<li>Ability to set Font Family and Font Sizes.</li>
<li>Full Screen and Preview Options</li>
<li>And many others.</li>
</ul>
Validated by: 
https://wpreadme.com/ 
https://wordpress.org/plugins/developers/readme-validator

Advanced Classic Editor

This plugin has the clean codes and has the best practice of doing the process.

Clearn Source


This plugin has only 1 competitor: "Advanced editor tools" by Automattic. I mention it because I tested both. Atomattic's only adds the table and top menu capabilities, while Advanced Classic Editor also add icons, buttons, alerts, and other bootstrap related stuff to make your life easier.



Also I just reported an error with font-awesome, which analyzed by plugin author, fixed and released within hours by plugin author = KUDOS to him!



Thanks to this plugin, I could get rid of three others which only added bootstrap shortcodes and tables. I cannot thank this author enough. This is real good and brings TinyMCE back to life again.



It surely can be expanded with more bootstrap stuff like other premium plugins, but that's the cost of free stuff and I'm willing to keep it that way.


Best TinyMCE addon

Advanced Classic Editor - Your powerful WordPress editor, Insert many Icons, Insert Table of contents, etc.

WordPress Accordion vs Advanced Classic Editor