GeoGebra CAS Calculator is an Android-based program developed by GeoGebra, available for free in the Education & Reference category. This program is a powerful math tool that makes it easy to graph functions, solve equations, find special points of functions, and share your results with friends and teachers. Millions of people worldwide use this app to learn math and science, and it is easy to see why.

With GeoGebra CAS Calculator, you can plot functions, polar and parametric curves, and solve equations with its powerful math engine. You can also experience transformations with sliders, get special points of functions, such as roots, min, max, and intersections, and find derivatives and integrals. Additionally, you can do regression with best-fit lines, search for free learning activities directly from the app, and save and share your results with friends and teachers.

Overall, GeoGebra CAS Calculator is an excellent math tool that offers a wide range of features and functionalities. It is perfect for students, teachers, and anyone who wants to improve their math skills. However, the app's interface may be confusing for first-time users. But, with a bit of practice, this app can be a powerful tool for learning math.