I think it was actually just a straight mobile clone as I see "WigglyPaint" in the screenshots and the original Android app was called WigglyPaint as well based on the url (/apps/details?id=io.wigglypaint.android). Probably got more popular than they were expecting and decided to pivot a bit.
I have two problems with that. One is, you can do what you like quietly and without disturbing anyone around you. Second is the Dunning Kruger effect: witnessing it first hand is never fun.