WPman

The plugin Slider comparison image before and after allows you to create the effect of comparing the two images before and after.
You can use the model vertically and horizontally. Used via shortcode [sciba].

Slider comparison image before and after

Slider comparison image before and after for your website to WordPress.

Daniel Ostman

Separator Widget inserts a horizontal rule ( <code><hr></code> ) or a custom div ( <code><div class="my-separator"></div></code> ) in your widget area. Each widget can be set to one of those options.
No extra styling is added so you are free to style them however you want it. 
Add your custom <code>hr</code> styling to your CSS or use <code>.my-separator</code> if you prefer that option.
Free and easy to use!
<a href="http://www.danielostman.se/" title="Visit WordPress developer web site" rel="nofollow ugc">More info about the WordPress plugin developer</a>

Separator Widget

A widget that inserts a horizontal rule or a custom div.

Slider comparison image before and after vs Separator Widget