Calfi is a free Android application designed to help individuals learn financial calculations, accounting, and related fields. It offers simple and compound interest calculations, rate of equivalence, and two different amortization systems.

The interface is straightforward and easy to use, providing users with a clean and organized space to input their data. The app allows users to calculate interest, present value, future value, time, and rate for both simple and compound interest. Additionally, it includes the Price-French amortization system and SAC-Constant amortization system.

One unique feature of Calfi is that it allows users to clean all fields by running their hand under the proximity sensor. This feature is not only convenient but also helps prevent data input errors.

Overall, Calfi is a useful tool for those learning financial calculations or working in related fields. The app is free, easy to use, and provides accurate calculations for various financial scenarios.