Na serveru Slunečnice.cz je zajímavá iOS aplikace:

Spiroids 1.6

What if you could draw with a brush that used spiroids as paint! Making geometric patterns on paper by pushing a pen through a hole in a disc and rotating it inside another disc can be a hours of fun. But what if the discs didn't have to be round? What if they could be square? What if they…

Adresa: https://www.slunecnice.cz/sw/spiroids/