From Peter Llewellyn-Davies:
Illusion is an optical illusion program for the Palm OS PDA. It has stunning graphics and comes in two versions, Illusion 3 for the monochrome Palm and Illusion 4 for the colour Palm 3c.
Illusion is for those of you who want to show your friends the graphical capabilities of your palm, to show your children or younger folk how the eye can deceive us but also as an enjoyable program to pass the time.
The story of Illusion started before 1994, I was fascinated of the various types of optical illusion around. The most famous illusions from Zollner, Hermann, Frazer and the CafÃ© House walls were inspiring. I had often been shown these illusions at presentations etc, but never found the time to look at and analyse the pictures in detail and in my own time.
After buying my first palm I never lost the idea of creating a software, which occupies the mind and the eye.... When Palm programming started to get easier I released Illusion Version 1 with 7 Illusions which was followed by Illusion Version 2 for the colour Palm with 10 illusions. These were freeware, with more than 10000 downloads, but some fans asked me if there was more.
The result is Illusion 3 and 4. These are the results of many months of programming.