This is a spy tool which enables you to spy on comments and likes beween facebook friends.
Example, if you are curious about how many comments or likes a facebook friend has received from one of their friends, you will be able to do so using this spy tool. You will actually be able to see those comments made and also whatever those "likes" where made on and the links to them.
This is a good plugin for you to know how engaging someone is with another person on facebook. And it can also be used between you and any of your friends to see how many comments or likes that friend or you have left on each others profile.