Strange question: I'm hoping that there exists some #opensource painting application (a much less powerful #krita , but in a browser) that could be used for a coloring book on desktop with a mouse or moblie with touch. Ideally it would have something akin to "layers" so that the coloring page image could remain "on top".
Before I go off trying to explain how to install a desktop application to young people unlikely to have access - or building a worse version in #p5js - I figured I'd ask! :)