Basically, it's a Flash application that fetches your friends and followers from Twitter when you click the "Whack!" button, then displays them for you, letting you quickly paginate through them. By default, the list contains all your friends and followers and is sorted by last update, showing those who most recently updated first. You can sort the list alphabetically either ascending or descending by Twitter ID. You can filter the list in several ways: only friends or only followers, all friends or all followers, and mutual friends.
Get fully manageable page with all friends, followers with avatars, where You can do several bulk actions as bulk follow, bulk unfollow, bulk block. Very handy.
Network actively with the right Twitter users, talk to them, spread their links, give them feedback, support their content. Be a participant in their Twitter experience.