(co-founder of Whimsical here) Thanks for the mention! Couple fun facts - Whimsical is written 100% in Clojure and we are self-funded (https://whimsical.com/business/why-bootstrap/).
I'm on Linux and just signed up. How do you pan around? The arrow keys work, but opposite the direction I'd expect. Don't see any panning tool obvious. Is the use case touchpads like on a Mac?
You can pan by holding down Space key (and then use mouse to drag the board). In general Whimsical's UX patterns are quite similar to Figma, Sketch and other UI design tools.
Cheers