This is a tool that you need. If you want to make life easy, and you want to get some more global reach I urgh you to use this tool. Just Google "Tweet Adder" you will see a lot of positive press on it plus plenty of videos showing you how it all works.
Why is it good?
You can search for people that tweet about your niche.
You can follow these people
You can unfollow people who have never followed you back after X amount of days
You can store tweets and tweet at times of the day
You can search for Bio data and find those people ie "SEO" find all people into SEO.
My Success
With my @BBFootballUK Twitter account I am almost at 4,000 followers who are all 100% legit. I got these by searching for people tweeting about football clubs and it has worked, I gain around 50 followers per day and its building up and up. Sometimes I tweet I gain over 120 Retweets which is just amazing because they all follow my niche.
Get it downloaded and try out the trial