Yield Spark Pro

Yield Spark Pro is a compound interest calculator built for anyone who wants to understand how their money grows over time.

Adjust your principal, annual interest rate, and investment period using smooth sliders. The app instantly recalculates and displays your projected growth through a clear, interactive chart. No typing required — just move a slider and watch the numbers update in real time.

The calculator supports both simple and compound interest modes, letting you compare outcomes side by side. You can set compounding frequency to daily, monthly, quarterly, or annually, depending on your actual investment terms.

All inputs are saved locally on your device. There is no account, no signup, and no server involved. Everything works offline.

The app includes a history section where you can save and name different calculation scenarios — useful when you want to compare a conservative estimate against an optimistic one without losing your previous inputs.

Settings let you choose between compact, card, or grid display modes, pick your preferred date and number format, and toggle haptic feedback.

A clean grid-based home screen gives you fast access to the calculator, your saved scenarios, and settings. The interface is minimal and focused — no clutter, no distractions.