Tweetadder is the answer.
I can store as many tweets I want and tweet them when I want.
Retweet whatever accounts I like however often I like.
Automatically follow, unfollow and much more.
Results are awesome and there are no monthly fees like in other apps..
Check out my twitter - http://twitter.com/cmelakigor - 30,000+ friends and growing!
Link to the tool ---> http://tinyurl.com/twittermanagerpro