Onboard

Onboard is a compact local-network web app for live board sharing. Open Board on a tablet, phone, or laptop, open Viewer in another browser or device, then share the Viewer tab in Google Meet while drawing privately from Board. Runs locally with a small Go relay and browser canvas — no accounts, no cloud. Supports whiteboard and blueboard marker tools, blackboard and greenboard chalk tools, pointer mode, ephemeral writing, and pasted, uploaded, or captured image backgrounds.