Marcin Choinski created a demonstration Dynamics of an Epidemic for Wolfram Demonstrations Projects.
Jan Gaska created a demonstration Geodesics on Some Surfaces for Wolfram Demonstrations Projects.
Elzbieta Kukla, Teresa Ponikowska and Michal Kijowski created a demonstration Coin Machine for Wolfram Demonstrations Projects. See below with Wolfram CDF Player or Mathematica:
Wolfram demonstrations of Dr Andrzej Kozlowski