Ray Diagrams is a free educational application developed by Audrius Meškauskas for Android devices. It provides an interactive demonstration of ray diagrams for converging or diverging lenses and mirrors, as well as a prism.

The application is user-friendly and easy to navigate. It offers a step-by-step guide that allows users to understand and visualize how light behaves when passing through different optical systems. The diagrams are clear and concise, making it easy for users to experiment with different variables and see the effects on the final image.

Overall, Ray Diagrams is a great tool for students and anyone interested in optics. It provides a fun and interactive way to learn and understand the principles of light and optics.