xsaber

This plugin will show a testimonial feed with star rating on your post, page or widget area using the shortcode <code>[tfeed_output]</code>.
Parameter: 
count: limit the number of feeds to show. (default: 4) 
Usage: <code>[tfeed_output count=2]</code>
I am planning to add pagination and front-end testimonial rating submissions in the next updates.

Testimonial Feed

A Simple WordPress Testimonial UI with Star Rating

David Shanske

Daniel Jalkut (Red Sweater)

mantonr

Adds a JSON Feed to your WordPress site by adding <code>/feed/json</code> to any URL.
The JSON Feed format is a pragmatic syndication format, like RSS and Atom, but with one big difference: it’s JSON instead of XML. Learn more at <a href="http://jsonfeed.org/" rel="nofollow ugc">jsonfeed.org</a>.

JSON Feed (jsonfeed.org)

This plugin is simple to install, adds no weight to your site, and does what it says on the tin.

Testimonial Feed vs JSON Feed (jsonfeed.org)