Plugin for related posts with thumbnails.
https://wordpress.org/plugins/wordpress-23-related-posts-plugin/
Widgets · WordPress Plugins
Get access to data on 148,292 websites that are WordPress Related Posts Customers. We know of 47,708 live websites using WordPress Related Posts and an additional 100,584 sites that used WordPress Related Posts historically and 25,927 websites in the United States.
Get a list of 148,292 websites using WordPress Related Posts which includes location information, hosting data, contact details, 47,708 currently live websites and an additional 22,920 domains that redirect to sites in this list. 100,584 sites that used this technology previously and 25,927 websites in the United States currently using WordPress Related Posts.