Compound Interest Calc is a free finance app developed by Dane Hankamer that uses a predictive formula to calculate the future value of your investments. The app aims to help users predict their future wealth by using compound interest, which is the interest gained on both the principal and the accumulated interest.

The app allows users to input their initial investment, monthly contributions, and interest rate. It offers flexible contribution frequency options such as yearly, quarterly, monthly, and weekly. The app also includes a guide for a comfortable retirement by displaying the investment value by year on a table and an interactive graph of investment value over time.

Additionally, users can easily toggle between Growth and Withdrawal modes to see how the investment value changes based on their preferences. The app ensures persistent values when switching between modes, so users don't have to re-enter their inputs.

Overall, Compound Interest Calc is a useful and straightforward app for anyone interested in predicting their future wealth through smart investments.