Mockingbird is no longer in operation. We’re hoping to open-source the code sometime in the near future. In the meantime, some simple alternatives, in a similar spirit to Mockingbird, are: Excalidraw: https://excalidraw.com TLDraw: https://www.tldraw.com If you need a more comprehensive mockup solution, you might want to check out the following: FigJam: https://www.figma.com/figjam/ MockFlow: http