Ivan Orlov and Gervais Chapuis have released an iPhone app to help teach crystallographic symmetry.
The app simulates the symmetry environment of the 17 planar (two-dimensional) symmetry groups which you can decorate with various objects. You can create colorful designs a la M.C. Escher and also effortlessly master the main crystallographic concepts:
- Planar groups
- Hermann-Mauguin symbols
- Symmetry operations
- Asymmetric unit
- General and special positions