Hacker Calculator is a free engineering calculator app for Android developed by Mohammed Benguedda. It offers a simple and user-friendly interface that allows you to perform four fundamental operations and engineering calculations on your Android device.

One of the unique features of this calculator is that it can be launched by rotating your phone, which is a convenient gesture for quick access. The app also stores your calculation history, which can be accessed by tapping the history button. You can even reuse previously inputted formulas by tapping on the desired formula from the history. The app is compatible with Android 9.0 and is a great tool for anyone who needs quick access to an engineering calculator on their Android device.