Just a few stats as of today : 

1. We have 326,000 registered users

2. Since launch we've seen over 115 million unfollows

3. On a regular day more than 0.5 million users get unfollowed using JustUnfollow

With JustUnfollow you can do the following: 

1. Show Non Followers - Find and unfollow users who do not follow you back

2. Show Fans - Find and follow users who follow you

3. Show Inactive Following - Find and unfollow inactive twitter users i.e. users who have not tweeted from a long time

4. Whitelist - Add users you do not wish to unfollow to the Whitelist

5. FriendFollower - Follow another twitter account's followers (currently being tested hence access to Premium accounts only). This helps you gain new followers in your niche since you can copy accounts that are similar to yours
6. FriendCheck - Find if a particular twitter user follows you and if you follow them