“Trello is a collaboration tool that organizes your projects into boards. In one glance, Trello tells you what's being worked on, who's working on what, and where something is in a process.”
I have personally used Trello for numerous projects for years and I can’t image working on a complex project without it. The quick and easy visual aspects of the application allows me to know what is going on, where projects are at, and who is assigned to what at a glance.
The real time updating allows multiple people to discuss projects and efforts in real time and the service also updates the mobile app immediately.
One of the initial points that steered me towards Trello was the mobile application. I am not separated from my projects while traveling or otherwise away from my PC.
There is a premium version of the software, but unlike other web/mobile apps, the vast majority of its usefulness is still in the free version of the application. .