WBO - Realtime collaborative whiteboard

Jira - The #1 software development tool used by agile teams. Jira Software is built for every member of your software team to plan, track, and release great software.

Miro - Scalable, secure, cross-device and enterprise-ready team collaboration tool for distributed teams. Join 2M+ users & 8000+ teams from around the world.

Excalidraw - Excalidraw is a whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them.

Kinopio - Thinking canvas for mind mapping, brainstorming, and moodboards

skribbl - Word guessing based on drawing.