Twitter follower is Chrome extension that helps you to mass follow and unfollow on Twitter.
It’s very easy to use: just install it, visit twitter.com and start following multiple accounts with only one click. If you change your mind, you can always “stop” the action or even “unfollow” all the previously followed users.
This tool, that lets you choose the time you want it to wait between clicks, also “scrolls” to the next account/user to simulate “human” behaviour and gives browser some time to load more suggestions or members you’ll be able to follow. Of course, it’s your responsibility to observe twitter limits to avoid being banned.