Paint Dropper

Open Paint Dropper and you are playing — a Hypercasual game that runs on the page rather than beside it. It is built for touch, so a phone or a tablet is the natural place for it. Its tags here are android, arcade, casual, color, coloring.

It is drawn for a tall screen, so it fills a phone held upright rather than a wide monitor. Everything runs client-side, so there is nothing to set up before you start.