It is very easy for you to use it.
First, you should login with your twitter account.
Second, in the main page, you can click the "Follow" button or the "UnFollow" button.
When you clicked the Follow button, you will get followers list, and click one item of them, you will
get a list of users who you not followed. Just follow them if you like.
When you clicked the UnFollow button, you will get a list of unfollowers who not follow you back,
Just click the "UnFollow" button to unfollow them.
Is it very wonderful for you ?
It is free for you to install it and using it!