Question 1

What does PennyBrew actually do?

Accepted Answer

It shows what small, recurring amounts become when they are invested instead of spent. Enter an amount, an expected annual return and a time period, and the app projects the future value, the total you contributed, the interest earned and the passive income that money would generate.

Question 2

How is compound interest calculated?

Accepted Answer

PennyBrew uses the standard future-value formula: FV = P × (1 + r)ⁿ + PMT × ((1 + r)ⁿ − 1) / r, where P is the initial amount, PMT the recurring contribution, r the periodic rate and n the number of periods. You earn returns on your contributions and on the returns they already produced.

Question 3

How much does the app cost?

Accepted Answer

PennyBrew is a one-time purchase of $1.99 on the App Store. No subscription, no in-app purchases, no ads.

Question 4

Does the app collect my data?

Accepted Answer

No. There is no account, no analytics SDK and no server. Every calculation, saved result and preference lives in local storage on your iPhone and is deleted when you delete the app.

Question 5

Does it work offline?

Accepted Answer

Yes. All calculations run on-device, so PennyBrew works in airplane mode and never needs a network connection.

Question 6

Which currencies and languages are supported?

Accepted Answer

More than 60 currencies including USD, EUR, GBP, JPY, CNY, RUB, UZS, KZT, TRY, AED, INR and BRL, plus Bitcoin and Ethereum. The interface ships in 20 languages, among them English, Spanish, Chinese, Arabic, Hindi, Russian, Japanese, German, Turkish and Uzbek.

Question 7

Is this financial advice?

Accepted Answer

No. PennyBrew is an educational calculator. Results are mathematical projections from the numbers you enter and do not account for taxes, fees or market risk. Talk to a qualified advisor before making investment decisions.

Question 8

What do I need to run it?

Accepted Answer

An iPhone on iOS 17.0 or later. The app is dark-mode native, supports Dynamic Type and VoiceOver, and needs no internet connection.