Does precisely what I want. I gave it four stars rather than five only because the interface is unintuitive. Changing the gearing and the pen colors should probably be separate Icons at the top of the screen rather than embedded within an icon that in most apps is reserved for sharing or exporting. Also, to make it obvious that values for gears or angles may be entered from a keyboard, the numerical values ought to (at least under some circumstances) be surrounded by a data entry space (white background). I only happened upon data entry by happenstance. I am grateful it’s there, but had I not found it, I’d have probably given up on your excellent program as too awkward to use.

Easy to use and, with a bit of experimentation and math, you can get exactly the shape & number of points you want. It would be even better if it exported vector graphics.

Draws perfect spirograph’s. No lag on mine. Maybe that other guy needs a better phone. Unlimited colors, & I don’t have to worry about the pen popping out of the hole, and messing up the design like when I was a kid. Perfect app, I love it

Simple, easy to use. Easier than I remember to keep the wheel on track and change things up than in the physical version.