Freedraw

Freedraw is a free version of Excalidraw with user accounts. You can share any canvas with anyone by email or by link, in the style of Google Docs. The product is available at freedraw.sh.

Freedraw also lets you be signed in to several accounts at once. Its creator, a consultant who works with several organizations, notes that Excalidraw+ allows only one signed-in account at a time. The creator says they love both Excalidraw and Excalidraw+.