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.
SmartWindows.app - Auto arrange all your app windows, whether on one screen or many with a single click!
GoodGantt - The best Gantt chart for Trello®
SANeForce - SAN Pharma Sales Force Automation
Paws for Trello - The best way to use Trello on your desktop
ReIcon - ReIcon is portable freeware that enables you to save and restore your desktop layout.