d3wp

Creates “Give Feedback” button in the right bottom corner of the post page. After click, redirects user to the comment box. 
This technique helps you to increase the number of user feedback
Uses jQuery for setting transparency when you move your mouse over the button (animated).
<h3>Feedback</h3>
http://www.webdev3000.com/

WD3K Give Feedback

Creates "Give Feedback" button in the right bottom corner of the post page. After click, redirects user to the comment box.

Arashtad

This product is a fully responsive WordPress widget and displays Testimonials in fancy styles. The widget output is very customizable and easy to work with. There are various options on the admin panel to take the appearance and behavior of each widget instance under your control. Some of the options are described below.
Features: 
* 4 Preset Styles 
* Custom Style Available 
* Customisable Width and Height 
* Customisable Header and Footer Texts 
* Customisable Margin and Padding 
* Fully Responsive 
* Unlimited Widgets on a Same Page 
* Ongoing Support 
* WordPress 4.x Compatible 
* FontAwesome Support 
And Much More…
Arashtad Testimonials Slider is created by <a href="https://arashtad.com/" rel="nofollow ugc">Arashtad.com</a> as a free WordPress plugin. But, though it’s a free product, it is fully supported by Arashtad.com.
<h3>Arbitrary section</h3>
Customization: 
As described this product is very flexible and easy to customize. You can easily change the style of its module output by editing the plugin CSS file at wp-content/plugins/arashtad-testimonials-slider/styles/master.css.

Arashtad Testimonials Slider Plugin

Arashtad Testimonials Slider Plugin creates unlimited Testimonials Slider widgets on WordPress websites.

WD3K Give Feedback vs Arashtad Testimonials Slider Plugin