Privacy Policy
StampWorth ("we", "us") is a mobile app that identifies postage stamps and estimates their value. This policy explains what data the app handles and why. We keep it simple because the app is simple: StampWorth has no accounts and does not ask for your name, email, or address.
In short: photos you scan are sent to our AI provider only to identify the stamp; we collect anonymous usage and app-performance data; and we never sell your data.
Information we handle
Stamp photos
When you scan a stamp, the photo (or the one you choose from your library) is sent to our AI identification provider, OpenAI, solely to recognise the stamp and estimate its value. Photos are transmitted for that request and are not used by us to build a profile of you. Photos and your saved collection are stored locally on your device; they are not uploaded to our servers or kept in the cloud by StampWorth.
Market lookups
To show market offers, the app may send the identified stamp name (not your photo or any personal information) to eBay to retrieve current public listings.
Usage & performance data
We use Google Firebase (Analytics, Crashlytics/performance and Remote Config) to understand how features are used and to keep the app stable. This includes anonymous events (e.g. "scan completed"), approximate device and app-version information, and a randomly generated app-instance identifier. It is not linked to your identity.
Install attribution
We use a first-party attribution system and Apple's AdServices (Apple Search Ads) to understand which marketing channel an install came from. This uses a first-party install identifier, Apple's attribution token on iOS, and on Android the Google Advertising ID together with the Play Install Referrer. These identifiers are sent only to our own servers, are used to count installs and attribute them to a marketing channel, and are never sold or shared with advertisers. You can reset or delete your Advertising ID at any time in Android Settings → Privacy → Ads. StampWorth does not show the App Tracking Transparency prompt and does not track you across other companies' apps or websites.
Subscriptions
StampWorth Pro is sold as an auto-renewing subscription through the Apple App Store. Apple processes the payment and your subscription status. We never see your payment card or billing details.
How we use data
- To identify stamps and estimate values (the app's core function).
- To show relevant market listings.
- To fix bugs, improve features, and measure which parts of the app are useful.
- To understand marketing performance in aggregate.
We do not sell your personal data, and we do not use your stamp photos for advertising.
Third-party services
The services above are independent providers with their own privacy policies:
- OpenAI — privacy policy
- Google Firebase — privacy & security
- Apple (App Store, AdServices) — privacy policy
- eBay — privacy notice
Data retention
Your scans and collection live on your device and are removed when you delete them or uninstall the app. Anonymous analytics are retained by our providers for a limited period per their policies.
Your choices
- Delete any saved stamp inside the app at any time.
- Uninstalling the app removes your local collection and photos.
- Manage or cancel a subscription in Settings → your name → Subscriptions on your device.
- You can limit ad measurement in iOS Settings → Privacy & Security.
Children
StampWorth is not directed to children under 13 and does not knowingly collect personal information from them.
Website analytics & cookies
This section covers our website at stampworth.app (including the blog). It does not describe the app, which is covered by the sections above.
We use Google Analytics 4 (a service of Google LLC) to understand how the website is used: which pages are viewed, how visitors arrive (for example from a search engine), approximate location (country or region, derived from the IP address — Google truncates the IP address and does not store it), browser and device type, and interactions such as clicks on download links. For this, Google Analytics sets first-party cookies on our domain (_ga and _ga_…, kept for up to 2 years) that recognise a browser on repeat visits. These cookies do not identify you by name, and we do not link website analytics to any app account or in-app data. Google processes this information on its own servers, which may be outside your country, under its privacy policy and its description of how Google uses information from sites that use its services. We keep analytics reports for 14 months and use them only to improve the website and its content — never for advertising.
Our hosting provider (Google Firebase Hosting) keeps standard server logs (IP address, time of request, pages requested, browser) for security and operations.
Your choices. You can block or delete cookies in your browser settings, install Google's Analytics opt-out browser add-on, or use a content-blocking extension — the website works fully without these cookies. If you have questions about analytics on the website, contact us using the details below.
Changes
We may update this policy as the app evolves. Material changes will be reflected here with a new "last updated" date.
Contact
Questions about privacy? Email us at support@ichime.dev.