Sadly, Tweet Adder is not free. I am not much of a twitter fan either but it is great when it comes to not having to spend a lot of time on twitter. You can simply set it and forget it and let it do the work for you. The $55 is well worth the investment in the long run.
Sorry it took me awhile to answer your question, and thank you for your comment Eddy2106
P.S. - I also wrote a hub on how to get a discount on tweet adder though - Search for Tweet Adder discount on hubpages and you will see instructions for a discount that can save you up to $37... I used the discount and I saved 20%.
have a great day