Twitter: Knowing and removing the people who aren't following me?

[supreme_zcaptain]

So I've followed a few people. Some of theme have followed me back. I want to remove some of the people who are NOT following me back. Right now it's rather easy because I'm only following 18 people and have 6 followers, but how do I keep track of who's not following (that I'm following) when I have hundreds of people in my following lists?

Thanks

[VIKAS]

There is a tool 'Unfollowers.me '.
You can see who followed you,
who you are following and following back,
who following you but not following back, etc.
All these are free.

They can also do the job of following back peoples and unfollow them if they stops following you. But this service is premimum.