ViralPress Lite is a very easy to use WordPress plugin to find Viral content from Facebook. ViralPress Lite helps you in finding and analyzing the content which went Viral in your business niche. Within a few seconds, you can easily find why is a particular Facebook page so popular by exploring its most popular (Viral) content using ViralPress Lite plugin.
Step by step documentation is here : https://indigothemes.com/documentation/viralpress-lite/
ViralPress Pro Features can be seen here : https://indigothemes.com/products/viralpress-pro-viral-content-finder-wordpress-plugin/