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.

Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.

Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.

Wrike - Wrike is a flexible, scalable, and easy-to-use collaborative work management software that helps high-performance teams organize and accomplish their work. Try it now.

Corrello - Dashboards for agile teams using Trello

TaskBoard - A Kanban-inspired app for keeping track of things that need to get done.