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

Danny van Kooten

ibericode

Harish Chouhan

<h4>WYSIWYG Widgets or rich text widgets</h4>
This plugin adds so called “Widget Blocks” to your website which you can easily display in your widget areas.
You can create or edit the widget blocks just like you would edit any post or page, with all the default WordPress editing functions enabled. This way, you can use the visual editor that comes with WordPress to format your widgets. You can even use media uploading to insert images and so forth.
Features:
<ul>
<li>Create beautiful widgets without having to write HTML code</li>
<li>Easily insert media into your widget content</li>
<li>Add headings, lists, blockquotes and other HTML elements to your widgets using the WordPress visual editor</li>
<li>Use WP Links dialog to easily link to any of your pages or posts from a widget</li>
<li>Use shortcodes inside your widgets</li>
<li>Translation ready</li>
</ul>
Translators
<ul>
<li>Dutch (nl_NL) – <a href="https://dannyvankooten.com/" rel="nofollow ugc">Danny van Kooten</a></li>
<li>Spanish (es_ES) – <a href="http://webhostinghub.com/" rel="nofollow ugc">Maria Ramos – WebHostingHub</a></li>
<li>Italian (it_IT) – <a href="http://www.dangelos.it/" rel="nofollow ugc">Tiziano D’Angelo – Studio D’Angelo</a></li>
<li>German (de_DE) – <a href="http://atelier.tag-eins.de/" rel="nofollow ugc">Christian Günther</a></li>
</ul>
If you have created your own language pack, or have an update of an existing one, you can send <a href="https://codex.wordpress.org/Translating_WordPress" rel="nofollow ugc">gettext PO and MO files</a> to me so that I can bundle it into WYSIWYG Widgets. You can <a href="https://plugins.svn.wordpress.org/wysiwyg-widgets/trunk/languages/wysiwyg-widgets.po" rel="nofollow ugc">download the latest PO file here</a>.
More information
<ul>
<li><a href="https://dannyvankooten.com/wordpress-plugins/wysiwyg-widgets/" rel="nofollow ugc">WYSIWYG Widgets</a></li>
<li>Other <a href="https://dannyvankooten.com/wordpress-plugins/" rel="nofollow ugc">WordPress plugins</a> by the same author</li>
</ul>

Widget Content Blocks

It does what it says and works well.
Great reusable widgets for multiple sidebars in WordPress.

Works well

This is such a great way to create widget content!

Works Wonderfully!

Edit widget content using the default WordPress visual editor and media uploading functionality. Create widgets like you would create posts or pages.

MarkdownBar vs Widget Content Blocks