What I do to draw in WigglyPaint on my iPad is use this page https://beyondloom.com/tools/wigglypaint.html and be able to use WigglyPaint without any problems
I also use Safari because it has the option to zoom in on the page, allowing me to zoom out as much as possible. I refresh it, and that way I can use WigglyPaint without it looking blurry
I would also like it to be on the AppStore or PlayStore, but unfortunately the engine of this app (Decker) is not fully compatible with mobile devices :(