Themeix

You can start collecting your endorsements or reviews in just a few simple steps. Both novices and experts will value the plethora of adaptable features developed over four years in response to user feedback and requests.
Live Demo : https://rst.yourdivi.com/

Really Simple Testimonials

Really Simple and Developer Friendly Testimonials.

Jeroen Sormani

Reviewer Rich Snippets is a extension to the <a href="https://wordpress.org/plugins/wpreviewer" rel="ugc">Reviewer</a> plugin.
The Reviewer Rich Snippets extension adds structured data to your reviews. 
Adding this structured data allows the search engines to read your review better and recognise that it is a review.
Search engines like Google can then decide to show rich snippets with your listing in the Search Engine Result Page (SERP). These ‘rich snippets’ are for example the star ratings you see with some listings.
The extension cannot guarantee rich snippets show up, the required data is added to the review, but ultimately the search engine decides with who to show the rich snippets. It can also take up to several months before the rich snippets are shown
This plugin requires no setup, just install and the additional markup is added to your reviews.
Documentation
We’ve extensively written documentation which can be found on <a href="https://wpreviewer.com/documentation" rel="nofollow ugc">https://wpreviewer.com/documentation</a>
Testing the added structured data
When the plugin is activated you can easily verify the structured data is added with the <a href="https://search.google.com/structured-data/testing-tool/u/0/" rel="nofollow ugc">Structured Data Testing Tool by Google</a>

Reviewer Rich Snippets

Increase the visibility of your review in the search engines by adding additional markup.

Really Simple Testimonials vs Reviewer Rich Snippets