Nifty - Manage projects, work, and communications in one place.
Taskade - Make lists, organize your thoughts, and be inspired to get things done. Taskade is a collaborative space for your tasks.
UnderPinned - One app to manage your projects from start to finish.
The New Dropbox - Enterprise software portal for team collaboration
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.
P2 - Share, discuss, and collab with your team. By Wordpress.