HeySpace - HeySpace is the only free task and simple project management software with communication and collaboration feature.
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.
Confluence - Confluence is content collaboration software that changes how modern teams work
Taskade - Make lists, organize your thoughts, and be inspired to get things done. Taskade is a collaborative space for your tasks.
Crucial Human - Crucial Human makes software focusing on human productivity, collaboration, and learning.
Google Workspace - Google's encompassing suite of cloud-based business apps.