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.
Taskade - Make lists, organize your thoughts, and be inspired to get things done. Taskade is a collaborative space for your tasks.
Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.
The New Dropbox - Enterprise software portal for team collaboration
Corrello - Dashboards for agile teams using Trello
P2 - Share, discuss, and collab with your team. By Wordpress.