If you are on Twitter then you know how it works – you follow people and they might follow you back. But it is not necessary that everyone you follow will follow you back.
He/She might follow you back only if your tweets are interesting or are of their interest. Instead of having to check the followers every now or then, there is a service that does the job for you. Are You Following Me Too is a dead-simple service for testing purpose only. It shows you the list of people whom you are following and they are not following you back.
This can come useful if you get few hundred followers and it becomes tiring to search for a specific person in the Following list.