Follow Tool for Twitter is a free Android app developed by darjjeelling that allows you to manage your followers on Twitter. It provides a simple and easy-to-use interface that allows you to know your followers who have unfollowed you, follow those who don’t follow you back, and unfollow those who you follow but don’t follow you back. You can also sort these lists by various ways and block users if necessary.

With Follow Tool for Twitter, you can manage multiple accounts without any additional fee and there are no annoying automatic tweets or messages by the app. The app also features a history graph that shows your follower count over time.

However, it is important to note that if you don't launch the app for more than five days, the list of people who unfollowed you and the new followers may not be created correctly. Additionally, if you have over 75,000 followers, followings, and blockings, the app may not function well due to TwitterAPI limits.

Overall, Follow Tool for Twitter is a useful app for anyone looking to manage their Twitter followers and keep track of their follower count.