Owlead - Grow your Twitter with valuable followers, effortless
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
TweetPilot - Grow a relevant & responsive following on Twitter
Slack - A messaging app for teams who see through the Earth!
MyFollowers - myfollowers.us is the answer to how to get more free followers on twitter. Start using www.
GrowthList - A crowd-sourced list of growth hacks