You Might want to check out Mashable.com and in their menu - Mashable Lists -Twitter. They have all kinds of list type posts on just about everything including tools. They give a pretty good break down of the things they list. Careful how you use automation a lot of people don't like that on Twitter. You can also get in trouble with Twitter.
I have been using TweetAdder for several months now. It's awesome, it does everything I was looking for in a Twitter software. ... and it works for both PC's and MAC's. - jens -
Be careful with sending automated messages to new followers. This is something that frustrates many people. My box is full of direct messages and I haven't read any because of that.
I never send direct messages. I schedule my tweets, and I target the people I follow and my followers. - jens -
Not long ago Twitter did a sweep and cleared a lot of accounts that were heavily automated. I was seeing my follower list count drop by the hour. They were people that had followed me but I was not following. I didn't know what was going on a first but found out in the support area. I don't auto follow I actually go to each persons page and make sure they are interactive and not just tweeting their own stuff. Like only their blog posts or just broadcasting affiliate links. I also check out their site or blog. Often people look like they have one but they don't. They buy a domain name and use it a a redirect to an affiliate sales page. They're still cleaning people out but I don't think they are dedicating their focus on it. But people are reporting it now that they know Twitter did a cleaning and are reporting similar profiles to @spam. So use automation with caution and it won't hurt to glance through Twitter's Rules and Policies section.
www.socialoomph.com is by far the best. You can automate things, but you can make it seem like it isnt a bot or anything.
Hi Arsham It's been a while but I came across this and remembered your thread. It looks like it does what you were looking to do. I am not using it myself so I can't tell you anything more about it. It's called Twitter Adder - tweetadder.com