Jay Holtslander

<a href="https://wpvulndb.com/plugins/structured-data-test-button" rel="nofollow ugc"></a>
Adds a “Test Data” link in the admin bar (when viewing any page or post) which opens the current URL in <a href="https://search.google.com/structured-data/testing-tool" rel="nofollow ugc">Google’s Structured Data Testing Tool</a>. (You must have the admin bar enabled to see it.)
<h3>Introduction to Structured Data</h3>
Structured data markup describes things on the web, along with their properties. For example, if your site has recipes, you could use markup to describe properties for each recipe, such as the summary, the URL to a photo for the dish, and its overall rating from users.
When you provide structured data markup for your online content, you make that content eligible to appear in two categories of Google Search features:
<ul>
<li>Rich results — Structured data for things like recipes, articles, and videos can appear in Rich Cards, as either a single element or a list of items. Other kinds of structured data can enhance the appearance of your site in Search, such as with <a href="https://developers.google.com/search/docs/data-types/breadcrumbs" rel="nofollow ugc">Breadcrumbs</a>, or a <a href="https://developers.google.com/search/docs/data-types/sitelinks-searchbox" rel="nofollow ugc">Sitelinks Search Box</a>.</li>
<li>Knowledge Graph cards — If you’re the authority for certain content, Google can treat the structured data on your site as factual and import it into the <a href="http://www.google.com/intl/es419/insidesearch/features/search/knowledge.html" rel="nofollow ugc">Knowledge Graph</a>, where it can power prominent answers in Search and across Google properties. Knowledge Graph cards appear for authoritative data about <a href="https://developers.google.com/search/docs/data-types/corporate-contacts" rel="nofollow ugc">organizations</a>, and <a href="https://developers.google.com/search/docs/data-types/events" rel="nofollow ugc">events</a>. <a href="https://developers.google.com/search/docs/data-types/reviews" rel="nofollow ugc">Movie reviews</a>, and <a href="https://developers.google.com/search/docs/data-types/tv-movies" rel="nofollow ugc">movie/music play actions</a>, while based on ranking, can also appear in Knowledge Graph cards once they are reconciled to Knowledge Graph entities.</li>
</ul>
<a href="https://developers.google.com/search/docs/guides/intro-structured-data" rel="nofollow ugc">Learn more</a>

Structured Data Test Button

I made this plugin

Adds a “Test Data” link in the admin bar (when viewing any page or post) which opens the current URL in Google's Structured Data Testing Tool.

Alexander

Open Graph Headers for WP plugin adds opengraph meta tags to head of all pages on your WordPress site. 
It does not add any page on admin part. There is no any features the plugin takes all data from posts and pages. 
The tags generated with this plugin are prepared with requires of published Opengraph standards (http://ogp.me/).

Open Graph Headers for WP

This plugin allows you to add open graph meta tags to your WordPress website.

Structured Data Test Button vs Open Graph Headers for WP