Hacker Calculator is a free Android utility tool developed by SIMPLE APPS that provides users with an engineering calculator for performing four fundamental operations and engineering calculations. This calculator app is designed to be versatile, allowing users to use the previously inputted formulas from the calculation history.

One of the unique features of the Hacker Calculator is that it can be started by rotating your phone. Additionally, users can check the calculation history by tapping the calculation history button, and close the calculation history page by pressing the phone return button. The app is compatible with Android 9.0 and can be used for various engineering calculations.

Overall, the Hacker Calculator is a useful tool for anyone working with engineering calculations, and its versatility makes it stand out among other calculator apps.