Twollo

Twollo is an auto follow tool that you can use keywords to target the people that you are following. Very useful tool, but it only seems to follow about 3 people an hour.

Twitter Karma

This too can help you clean out your twitter account. If you have alot of people that you are following, and they are not following you, you can use this tool to bulk unfollow. Check out Twitter Karma.

Secret Tweet

Secret Tweet is a tool that allows you to send tweets anonymously. Just put your tweet in the box, and hit submit. The drawback is that it can take awhile for the moderator to approve your tweet.

Tweet Smarter

Tweet Smarter takes tweeting to a whole new level. Not only can you type in special characters, you can also send out a retweet link with your tweet. Check it out. Click Here