HeySpace - HeySpace is the only free task and simple project management software with communication and collaboration feature.
Taskade - Make lists, organize your thoughts, and be inspired to get things done. Taskade is a collaborative space for your tasks.
The New Dropbox - Enterprise software portal for team collaboration
Flow - Stop managing projects from your inbox.
P2 - Share, discuss, and collab with your team. By Wordpress.
Foore - Customer communication & team collaboration platform