Excalidraw

Excalidraw is an open-source virtual whiteboard whose whole personality is the hand-drawn line — sketchy, deliberately unfinished, low-stakes enough that nobody mistakes a wireframe for a decision. This flow walks the argument it makes across three surfaces: the editor itself, which drops you onto an infinite canvas with no account and no onboarding; the Excalidraw Plus marketing site, which sells the same simplicity plus real-time collaboration and AI; and the wireframe use-case page, where the sketchy aesthetic gets reframed as a professional design tool with a wireframe-to-code payoff. The through-line is friction removal: the tool works before it asks for anything, and the paid tier sells the team layer on top of a habit you already have.