Related posts widgets are necessary for any blog in order to engage your visitors , have an internal links juice and increase page rank of many posts for your own blog there are three famous related posts tools for blogger , wordpress and other platforms
1- Outbrain:
Using outbrain can pick your related posts widget with or without thumbnains out brain will give you a full report and statistics about related posts activity.outbrain used to have embeded rating for posts but not any more ! out brain will display some sponsored links if your website doesn`t have enough related posts
2- Linkwithin:
Famous linkwithin will offer you related posts widget without any need to register Linkwithin is a completely ad free service there are two option for light and dark themes .linkwithin is fast and simple
3- nRelate
nRelate is similar to outbrain it will give you full reports and you can make money using it`s ad program also it`s very customizable widget but it takes some time about an hour or more to display :(
4- Classic related posts:
The 1st related posts i met may be three years ago! it`s a handy hack but still works :)
blogger widgets