How it works
A picture under a layer of grime. Hold and move to wash it off. Every pass shows a little more.
Drag your finger or mouse across the picture. Go over the same spot twice to get it fully clean. The thin bar underneath fills as you go, with no number. When it's clean, it says so, and another picture is ready when you want one. Turn on sound for a quiet spray. Three pictures, three brush sizes, nothing timed.