A free program for Android, by Mr Duy.

This is a free scientific calculator app for Android. The app features a rich and detailed set of mathematical functions. It can calculate many different types of graphs and calculate the area under a curve. It can also calculate the roots of a polynomial and find the intersection of two lines. You can also use it to find the square and cube of a number.

The app has a simple and intuitive user interface. You can enter your equations as you would on paper and calculate the answer. In addition, it is designed to work offline. It does not require any internet connection to work. Plus, it works on most Android devices.