Privacy Policy

Last updated: 20 September 2026

This policy explains how the ProsperFolio app for Android ("ProsperFolio", "the app") handles information. ProsperFolio is published by A4 Apps ("we", "us").

1. Information stored on your device

To work, the app stores the following on your phone. None of it is sent to us.

• Brokerage connection details – the API key and secret you enter. These are encrypted using the Android Keystore, which keeps the encryption key in secure hardware on your device.
• Connection settings – connection names and, for custom connections, the server address you configure.
• Manual holdings – symbols, share counts, costs and purchase dates you add yourself.
• Watchlist – the symbols you follow, and the share price at the time you added each one.
• Preferences – display currencies, refresh interval, widget style, price-alert settings and app-lock settings.
• A cached portfolio summary – so the home screen widget can show your latest total.

App data is excluded from Android cloud backup and device-to-device transfer, so it is not copied to Google's servers or to another phone.

2. Services the app connects to

When you use a feature, the app communicates directly from your device with the following services, always over encrypted (HTTPS) connections. We do not operate or receive data from these connections.

• Your brokerage – Alpaca, Trading 212, Interactive Brokers (Flex Web Service), eToro, Tradier, or a custom API you configure. The app sends the credentials you entered for that broker directly to it, to request your account balance, positions and, where the broker provides them, portfolio history and company names. If you connect Alpaca, the app may also use that connection for market prices and news headlines where its free data covers a symbol. Each broker's own privacy policy applies to that information. Any request that could change your account, place orders or move funds is blocked inside the app.
• Yahoo Finance (query1/query2.finance.yahoo.com), for share prices, price history, ticker search and published company statistics (P/E, EPS, market cap, beta, analyst target and trading ranges). These requests contain only the ticker symbols or search text involved — no account information, and no credentials. Prices from this source are delayed, typically by around 15 minutes.
• ExchangeRate-API (open.er-api.com), to fetch daily currency exchange rates. No personal information is sent.
• News publishers – Yahoo Finance, Google News, Nasdaq, MarketWatch, Investing.com and Seeking Alpha. The app reads their public headline feeds, requesting only headlines, publisher names, dates and links. The tickers you hold are included in those requests so the stories are relevant. Opening a story takes you to that publisher's own website.
• Google Play, if you subscribe to ProsperFolio Pro. Payment is handled entirely by Google; we never see your payment details. The app receives confirmation from Google Play that your subscription is active so it can unlock brokerage connections. Google's privacy policy applies to purchases.

As with any internet request, these services will see your device's IP address.

3. Information we do not collect

We do not collect your name, email address, location, contacts, photos, device identifiers or advertising ID, and we do not use analytics, advertising or crash-reporting software. If you email us for support, we will receive the information you choose to include in your message.

4. Biometric unlock

If you turn on app lock, fingerprint, face or PIN verification is carried out by Android. The app only learns whether verification succeeded; it never receives your biometric data.

5. Price alert notifications

If you turn on price alerts, the app asks Android for permission to post notifications and checks your holdings and watchlist prices in the background, roughly every 15 minutes. The comparison and the notification are produced entirely on your device; nothing about your holdings, your alerts or the notifications is sent to us or to anyone else. Turning the setting off in Settings stops the background checks.

6. Keeping and deleting your information

Your information stays on your device until you remove it. You can delete a brokerage connection (and its encrypted keys) in Settings, and remove manual holdings and watchlist entries at any time.

To erase everything at once, use Settings → Delete account → Delete account & data. That permanently removes every connection and API key, your manual holdings, watchlist, price alerts, preferences and cached totals from the device, and cannot be undone. Because there is no ProsperFolio account on any server, there is nothing else for us to delete and nothing for you to request from us. Uninstalling the app has the same effect. A Pro subscription is separate: manage or cancel it in the Google Play Store.

7. Security

API keys are encrypted with the Android Keystore, all network traffic uses HTTPS, the app blocks screenshots and screen recording of its screens, and you can require biometric or PIN unlock. No method of storage or transmission is completely secure, so we recommend using read-only or paper-trading API keys where your brokerage offers them.

8. Children

ProsperFolio is intended for adults aged 18 and over and is not directed at children.

9. Your rights

Under UK and EU data protection law you have rights over your personal data, including access, correction and deletion. Because we do not hold personal data about app users, most requests can be met by managing the data on your own device as described above. For purchase records, contact Google Play. If you have a question or concern, contact us below; you can also complain to the UK Information Commissioner's Office (ico.org.uk).

10. Changes to this policy

If we change how the app handles information, we will update this page and the date at the top before the change takes effect.

11. Contact

A4 Apps
Email: a4appsuk@gmail.com
Website: www.a4apps.co.uk

We are a small independent developer with no public office address; email reaches us directly and is the fastest way to get an answer, usually within 2 working days.