https://www.theverge.com/2018/7/12/17563896/microsoft-whiteboard-app-windows-10-ios-web

Microsoft is launching its collaborative Whiteboard app on Windows 10 today, and promising versions for iOS and the web soon. The app has been in preview for Windows 10 for the past seven months, and it’s now being made widely available on PCs alongside a new version for the web and iOS devices. Whiteboard lets users make notes on a virtual whiteboard that can be shared and edited with others in real time across devices.

Anyone can access the app, but to collaborate with multiple people at least one person in the group will need an Office 365 subscription. Whiteboard supports inking on Windows 10 so styluses like the Surface Pen can be used for collaborative inking, geometry recognition, table conversion, and automatic table shading. Whiteboard users have been using the app to write out process flows, create tables collaboratively, and brainstorm presentations.