It's a simple bot I wrote a couple of years ago to play with Twitter social interactions.
- follow every follower you have
- 2 days after your follow, unfollow everyone that is not following you back
It is really simple to configure and use: provide a configuration file (-c <path_to_configuration_file> )
Moreover, you can add a 'target'. This could be a user similar to you. This software takes a list of his/her followers and follows them.
BTW, I'm pretty sure it violates twitter's terms of service.