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.
Dialogflow - Conversational UX Platform. (ex API.ai)
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Botpress - Open-source platform for developers to build high-quality digital assistants
Slack - A messaging app for teams who see through the Earth!
Messenger Platform - Discovery, chat extensions, and richer experiences