I know what you’re thinking, “Ryan, haven’t you mentioned about a million whiteboard apps?” Maybe I have, but each one has their own pros and cons.
Excalidraw is pretty cool, it throws you right in to a whiteboard ready for you to create. The tools are along the top of the screen and work as you would expect. Where Excalidraw becomes a lot more fun is when you collaborate with others and add libraries.
You can invite others to your whiteboard by clicking on the two person icon in the upper left. Excalidraw gives you a url that you can share with others. No accounts needed.
On the right side of the toolbar is an icon that looks like a book. This takes you to the Excalidraw libraries site, which lets you add different sets of libraries to your whiteboard. Libraries in this context can be thought of as clipart.