Be carefully with Twitter follower exchange sites because you can get some law quality followers. I only recommend WeFollow and Twiends. They can help you probably.
stick with twiends.com, it is definitely the fastest. Plus they come down hard if someone follows you and then unfollows you. They put a limit on your account if you do so a certain number of times. Plus it is very easy to follow people, on most other websites, you actually have to follow them manually and it is a pain in the butt. Plus, their are a lot of users on twiends. I would say just stick with that.
Use Addmefast and YOUlikehits with imacros never crushing scripts and twiends. Just use the update robot and you can have your followers in no time.But be careful Twitter is more stricter that old days.
Twiends is no longer a viable option to get actual Twitter followers, the people who follow you are mostly 'Bots' that are farming followers to sell the Tweets.. Keeko.com is a website I have found to work really well in terms of getting Twitter followers and to a lesser extent, Google+ 1's It is free to use and they give you the option to purchase points if you want to speed up the process - I purchased the $19 package and have found that it speed up the process considerably. Youlikehits is another good option for getting lots of followers! but I found that the unfollow rate is much higher (20 out of every 100 stay following you) Or of course... you could just use Twitter how it was designed and manually follow people you are interested in? Anyways hopefully this was useful! give Keeko.com and Youlikehits.com a try!'
A way to get a lot of followers on twitter is SEO Clerks really. I have done some work for them for a while now and I have gotten a lot of followers from just working there as a free lancer.
addmefast.com is a good way to do it. You can also use this to get likes on facebook or followers on instagram or stumbleupon and many others