Tools for Cooperation

Notion - https://notion.so - wiki for orgs

Slack - https://slack.com - chat

Trello - https://trello.com - cards / prioritization

Figma - https://www.figma.com/ - interface design / wireframes

GitHub / Gitlab - source code server / pull requests

tmate - https://www.figma.com/ - share terminal over internet

I have used dropbox paper to collab on things in realtime, but not sure what kind of reply you were looking for.

I think that it depend what you need to cooperate with.