Calc Visualizer helps the user better understand some of the most important concepts of calculus. The app includes eight different modules: 1) Descartes' Method, 2) Fermat's Method, 3) Derivatives, 4) Areas under Curves, 5) Fundamental Theorem, 6) Slope Fields, 7) Max-Min problems, and 8) Related rate problems. Highly interactive, but with extensive instructional help screens and animations.