crimson090

Adds buttons to the Text (HTML) edit which generate Markdown syntax. These buttons serve as a great introduction to 
users who are new to Markdown, as well as shortcuts for more experienced users. The buttons include:
<ul>
<li>Bold</li>
<li>Italic</li>
<li>Blockquote</li>
<li>Link</li>
<li>Code</li>
<li>Table</li>
<li>Headers</li>
<li>Help (links to external Github Markdown guide)</li>
</ul>
This plugin does not modify the Visual editor, as that editor is not ideal for writing Markdown in. It’s recommended you disable 
the Visual editor entirely to enforce using Markdown.
Note that this plugin does not render Markdown. You should use a plugin (such as Jetpack Markdown) to render markdown in your theme.

MarkdownBar

Adds a toolbar of buttons to the Text (HTML) edit which generate Markdown syntax

arickards

tinyWYM Editor was created to help inexperienced WordPress users create cleaner, more semantic markup, and to avoid some of the pitfalls of WordPress’s standard WYSIWYG editor. It does this by labelling and highlighting all HTML elements in the editor, creating a visual representation of the HTML being generated.
tinyWYM Editor also gives more experience users all the control and flexibility of the text editor without having to leave the visual editor. Create and edit any HTML element, add attributes, and wrap or unwrap elements all from the visual editor.
See the <a href="https://wordpress.org/plugins/tinywym-editor/screenshots/" title="Screenshots" rel="ugc">Screenshots</a> and <a href="https://wordpress.org/plugins/tinywym-editor/faq/" title="Frequently Asked Questions" rel="ugc">FAQ</a> sections for details on how to use tinyWYM Editor.

tinyWYM Editor

At long last: Now we can see the container hierarchy while editing visually, and manipulate it too!
The plugin author is quick to respond, clear friendly and helpful.
Unreserved recommendation!



Fantastic

Convert WordPress's WYSIWYG editor into a WYSIWYM editor. Add and edit any HTML tag and attribute from the visual editor.

MarkdownBar vs tinyWYM Editor