Sami Ahmed Siddiqui

Search engines such as Google are using structured data markup in many ways—for example, to create rich snippets in search results. Search results with rich snippets will improve your click through rates and increase the number of visitors on your website.
This plugin helps:
<ul>
<li>Helps your site to earn rich snippets in Google’s SERP.</li>
<li>Does not depend on other plugins or external code.</li>
<li>You can configure the plugin from the settings page.</li>
<li>You can activate schema’s according to your requirement. Multiple schema types are available.</li>
</ul>

JSON Structuring Markup

JSON Structuring markup is simply the easiest solution to add valid schema.org as a JSON script in the head of posts and pages.

MarcusPope

J-Ro

Azragh

This plugin preserves the user-generated HTML markup in the TinyMCE editor. Unlike other plugins this one allows developers to work in the HTML tab AND end-users to work in the WYSIWYG Visual tab at the same time! No longer will your HTML markup be completely munged into an unrecognizable form when you switch between those tabs. And you don’t have to hang your users/editors out to dry when you hand off the project with a disabled Visual tab.
<h4>IMPORTANT: Please read the installation instructions carefully. If you have existing content it will not render properly after activating this plugin until you use the Fix It Tools.</h4>
(One user didn’t read or follow these steps and panicked thinking I ruined their website.)
It also supports HTML5 Block Anchor tags in addition to other HTML5 elements, something that is currently not supported in WordPress via any existing plugins.

Preserved HTML Editor Markup Plus

Preserves HTML and developer edits in HTML AND WYSIWYG tab.  Supports inline scripts/css, JavaScript code blocks and HTML5 content editing

JSON Structuring Markup vs Preserved HTML Editor Markup Plus