Privacy Policy

Stamp Identifier & Value (Android) | Identify My Stamps (iOS)

Last Updated: August 16, 2026

1. Introduction

This Privacy Policy describes how Stamp Identifier ("we," "our," or "us"), developed and operated by Viksva, MB, a company registered in Vilnius, Lithuania, collects, uses, and protects your personal information when you use our mobile application and services. We are committed to protecting your privacy and handling your data transparently in accordance with applicable data protection laws.

2. Information We Collect

2.1 Information You Provide Directly

• Stamp Images: Images of stamps you submit for identification and valuation analysis (front and back)
• Contributed Reference Data (optional, opt-in only): If — and only if — you enable "Contribute scan photos", a sanitized copy of the FRONT image of stamps you scan, together with the AI identification result, is stored on our servers to build a private stamp reference database. See Section 5 for full details. This never happens without your explicit consent.
• Identification Reports (optional): If you use "Report a problem" on an identification, the report you submit (which details you marked wrong and any structured corrections you typed) is stored on our servers to improve identification accuracy. Reports contain no free-text field and no account, name, or email. They do carry a one-way hash of your app installation's anonymous sign-in identifier, so that your reports can be found by "export my data" and removed by "delete my data".
• Collection History: Records of stamps you have identified and saved
• User Preferences: Preferred identification mode (stamps, coins, banknotes, antiques), display settings
• Subscription Status: If you purchase a subscription. The app has no accounts and no sign-up — you never give us a name, email address, or password. Payments are handled by your app store, and subscription status is managed by RevenueCat under an app-generated anonymous identifier (Section 6.2)
• Support Communications: Messages you send to our support team

2.2 Information We Collect Automatically

• Usage Data: App usage patterns, features used, time spent in app, stamps identified
• Device Information: Device model, operating system version, app version, and device identifier (device ID)
• Anonymous Identifiers: An app-generated anonymous sign-in identifier, a RevenueCat app user identifier, and — if you contribute scan photos — a contributor identifier. These are pseudonyms created by the app or its processors. None is linked to your name, email address, or any account. They exist so that the app can deliver your subscription and so that "export my data" and "delete my data" can find your data and nobody else's
• Stability Data: We do not integrate any crash-reporting service into the app. Apple and Google make aggregated crash and performance statistics available to us through App Store Connect and Google Play Console; that data comes from the operating system rather than from the app, and does not identify you
• Analytics Data: App events, user interactions, and usage statistics collected through Google Analytics (see Section 6.3)
• Purchase Data: Purchase history and subscription activity, collected through RevenueCat (Section 6.2) and, where analytics consent applies, Google Analytics (Section 6.3)
• Feature Usage: Number of identifications performed, feature usage patterns

2.3 Camera and Storage Permissions

Camera Permission: We request camera access to allow you to take photos of stamps for identification and valuation analysis. When you use the camera feature:

• Photos are captured directly within the app for stamp identification through AI image analysis
• Images are stored locally on your device for access in your collection history
• Images are transmitted to Google Gemini AI services for processing and identification analysis
• Images sent to Google are processed temporarily and are NOT stored for long-term storage by Google according to their data retention policies
• We do not store your photos on our own servers, UNLESS you have explicitly opted in to the contributed reference database described in Section 5 — in that case a sanitized copy of the front image of stamp scans is stored on our servers, and you can delete it at any time
• Because images are also processed by Google during identification, we CANNOT delete the copies transiently processed by Google - their retention is governed by Google's privacy policies. We CAN and DO delete any contributed copies stored on our own servers when you ask us to (Section 5)
• You can delete images stored locally on your device at any time through the app's history screen

Storage Permission: We request storage access to save stamp images and identification results locally on your device so you can view them from the history screen. These locally stored images can be deleted by you at any time.

3. How We Use Your Information

We use your information for the following purposes:

• Stamp Identification: Processing your stamp images through Google Gemini AI services to analyze and provide identification, condition grading, and approximate valuations
• Collection History: Storing identification records and images locally on your device for reference (EDUCATIONAL/ENTERTAINMENT PURPOSES ONLY)
• Reference Database (opt-in only): If you consent, storing contributed stamp images and AI identification results to build and improve a private stamp reference database (Section 5)
• Identification Accuracy: Storing and reviewing identification-issue reports you choose to submit, to find and fix identification errors
• Service Provision: Delivering core app functionality and premium features
• Usage Tracking: Managing daily usage limits for free users
• App Improvement: Analyzing usage patterns to enhance user experience
• Customer Support: Responding to your inquiries and providing assistance
• Legal Compliance: Meeting legal obligations and protecting our rights

4. Legal Basis and Consent for Contributed Data (GDPR)

For users in the European Union / EEA, the United Kingdom, and Switzerland, contributed reference data (Section 5) is processed exclusively on the basis of your explicit consent (GDPR Art. 6(1)(a)). Consent is:

• Off by default — no contribution happens until you actively enable it
• Purpose-specific, and split into two separate choices — (a) private storage for the reference database, and (b) publication of approved photos in our public stamp catalog. These are asked as two independent checkboxes. Choice (a) alone never results in anything being published. Choice (b) is only available together with (a), because publication needs a stored photo to publish, and it can be withdrawn on its own while (a) continues
• Versioned independently — we record which version of each consent text, of the catalog display licence, and of this policy you agreed to. If the meaning of either consent materially changes, that purpose stops until you agree to the new terms. A change to the publication wording never affects your private-storage consent, and vice versa
• Withdrawable at any time — turning either toggle off in Settings stops that purpose immediately. When you turn off private contribution, the app also offers to delete everything you have already contributed; you can decline and delete later instead. Deleting your contributed data removes what was stored (Section 5.5). Withdrawing is as easy as consenting

5. Contributed Reference Database (Optional, Opt-In Only)

To improve stamp identification for everyone, you can optionally allow us to keep a private copy of your stamp scans, and — as a separate, additional choice — allow approved photos to appear in our public stamp catalog. This section describes exactly what each of those means.

5.1 What is stored, and how

• Front image only: Only the front image of stamp-mode scans is stored. Back images are never stored. Scans in coin, banknote, or antique mode are never stored
• Sanitized before storage: Images are re-encoded on our servers before storage. All camera metadata (EXIF, GPS location, device information embedded in the file) is removed, and images are resized
• AI identification result: The structured identification produced for that scan (country, year, denomination, catalog number, and similar stamp facts) is stored with the image
• Pseudonymous storage: Contributions are linked to a random contributor identifier, and to a one-way hash of your app installation's anonymous sign-in identifier — never to your name, email, or profile. We keep that link for one reason: so that "export my data" and "delete my data" can find your contributions and nobody else's. It is not used to build a profile of you
• Private by default: Contributed data is stored in access-controlled Google Cloud infrastructure (Firestore and Cloud Storage, see Section 12). It is never sold, and never shared with third parties. Unless you separately opt in to catalog publication (Section 5.2), it is not publicly accessible and not shown to other users

5.2 Catalog publication (separate opt-in)

"Allow catalog publication" is a second, independent choice. If you leave it off, nothing you contribute is ever published. If you turn it on:

• Nothing publishes automatically. Being eligible is not the same as being published. Every contribution is stored as unreviewed and private. A photo can only appear in the catalog after it passes our review, and we check your publication consent again — as it stands at that moment, not as it stood when you scanned — immediately before anything is published
• What may appear: the sanitized front photograph and the verified stamp facts associated with it. Your contributor identifier, your installation identifier, and any hashes of them are never published
• Licence: you grant us a non-exclusive, worldwide, royalty-free licence to display and resize your photograph in the catalog and in the app. You keep ownership. This licence covers your photograph only — it does not and cannot cover the design of the stamp itself, whose copyright belongs to the issuing postal authority. See the Catalog Display Licence
• Unpublishing, and its honest limit: turning this off — or deleting your contributed data — removes your photo from our catalog. But once an image has been publicly visible, other people and search engines may already have copied, cached, or indexed it. We can remove our copy. We cannot recall copies that others have made. Please take this into account before opting in
• Withdrawal is independent: turning catalog publication off leaves your private contribution consent untouched, and vice versa
• Other people's data in your photo: please photograph the stamp only. Stamps still on an envelope or postcard can show a third party's name, address, or handwriting. Our review rejects any image in which personal data of any person is legible; such images are never published, regardless of your setting, and remain private (or you can delete them). We remove any published image on request from a person shown or named in it

5.3 Deletion code

When you first opt in, the app shows you a one-time deletion code. This code exists for one purpose: it lets you delete your contributed data even after you reinstall the app or switch devices (which would otherwise sever the link between your installation and your contributions). Save it somewhere private. The code can only delete data — it cannot read or download anything. We store only a cryptographic verifier of the code; if you lose your saved copy, we cannot recover it (you can generate a replacement in Settings while still on the same installation).

5.4 Your controls, in the app

• Contribute scan photos (Settings toggle): Turning this off stops all future contributions immediately, and also ends any catalog publication. We then ask whether you also want to delete what you have already contributed. If you decline, that data remains stored until you choose to delete it
• Allow catalog publication (Settings toggle): Turning this off removes your photos from the public catalog and stops any further publication, while leaving your private contributions in place
• Export my contributed data (Settings): Downloads a complete copy of everything we store about your contributions — your consent record, contributed images, scan records, and any identification reports you filed — as a ZIP archive (GDPR Arts. 15 and 20)
• Delete contributed data (Settings): Permanently deletes your contributed images, scan records, identification reports, published copies, and derived private records from our servers, and stops future contributions. If you are on a new installation, enter your saved deletion code to also remove contributions made from the earlier installation

5.5 What deletion covers

Deletion removes, from our servers: contributed images and all derived image copies (including any published catalog copy), the scan records stored with them, identification reports you filed, your consent record's identifying details, and the deletion-code verifier. A minimal, anonymized audit record of the deletion (containing no images and no identifiers usable to re-identify you) is retained for up to 24 months as evidence that the deletion was performed. Aggregated, fully anonymized stamp facts that no longer contain any link to you or your images may be retained. As noted in Section 5.2, copies of a previously published image already made by third parties are outside our control.

5.6 Retention

Contributed data is retained while your consent remains active, and is reviewed periodically (at least every 24 months) to confirm continued need. Withdrawing consent stops collection immediately and prompts you to delete what was already stored; deletion removes stored data as described above.

6. Third-Party Services

We integrate with the following third-party services. These services have their own privacy policies and terms of service, and we are not responsible for their data practices:

6.1 Google Gemini AI

Stamp images are processed using Google Gemini AI services for identification and valuation analysis. Data is sent to Google's AI services for temporary processing. IMPORTANT: AI can and will make mistakes - identifications and valuations may contain significant errors or be completely incorrect. Key points about Google Gemini AI processing:

• Image Transmission: When you take a photo for identification, the image is transmitted to Google Gemini AI for analysis
• Temporary Processing: Images are processed temporarily by Google and are NOT stored for long-term storage according to Google's data retention policies
• No Deletion Control: Because identification images are processed by Google, we CANNOT delete the copies transiently handled by Google. Image retention and deletion there are governed solely by Google's privacy policies. This is separate from opt-in contributed copies stored by us, which we CAN delete (Section 5)
• Google's Responsibility: Processing of your data by Google Gemini AI is governed by Google's Privacy Policy, and we have no control over or responsibility for their data practices
• No Liability: We have ABSOLUTELY NO LIABILITY for how Google handles, processes, stores, or retains your images

6.2 RevenueCat and Subscription Management

We use RevenueCat to manage premium subscriptions and in-app purchases. When you subscribe to premium features:

• Payment Processing: All payments are processed through your device's app store (Apple App Store or Google Play Store)
• Subscription Data: RevenueCat collects and processes subscription status, purchase history, and payment information
• User Identification: RevenueCat may assign unique user IDs to track subscription status across devices
• Data Sharing: We receive anonymized subscription status information from RevenueCat to enable premium features
• Third-Party Processing: RevenueCat processes subscription information according to their privacy policy, and we are not responsible for their data handling practices

Subscription Plan Details:

• Weekly Subscription: Includes a 3-day free trial period. Billing begins automatically after the trial expires unless cancelled
• Yearly Subscription: No trial period. Billing begins immediately upon subscription
• Automatic Renewal: All subscriptions automatically renew unless cancelled through your app store account before the current period expires
• Trial Cancellation: You can cancel during the trial period to avoid charges

6.3 Google Analytics

We use Google Analytics to understand app usage and improve our services. Google Analytics collects the following data:

• App Events: User interactions and actions within the app, such as screen views, button taps, feature usage, stamp identifications performed, and other in-app activities
• Device Identifier (Device ID): A unique identifier associated with your device, used to distinguish users and track usage patterns across sessions
• Purchase History: Information about in-app purchases and subscription transactions, including purchase events, subscription status changes, and transaction details

This data is collected and processed by Google in accordance with Google's Privacy Policy. We use this data solely to analyze app performance, understand user behavior, and improve our services. We do not sell this data to third parties. You may opt out of Google Analytics data collection by adjusting your device's advertising and tracking settings.

6.4 Third-Party Disclaimer

7. Data Storage and Security

• Local Storage by Default: Unless you opt in to the contributed reference database (Section 5), all personal information and stamp images are kept on your mobile phone only and are NOT stored on our servers
• Opt-In Server Storage: If you enable contribution, sanitized front images of stamp scans and their AI identification results are stored on our servers as described in Section 5, under your control, until you delete them
• Temporary Third-Party Transfer: Stamp images are transferred to Google Gemini AI services for temporary processing and identification analysis
• Access Controls: Server-stored contributed data is protected by deny-all client access rules — it can only be reached through our authenticated, verified server functions, never directly by an app or browser
• Google Processing: Images sent to Google Gemini AI for identification are processed temporarily and are NOT stored for long-term storage by Google according to their data retention policies
• Deletion Control: We CAN delete contributed copies stored on our own servers (Section 5.5). We CANNOT delete the copies transiently processed by Google during identification — their retention is governed by Google's privacy policies, nor copies of an already-published catalog image that third parties have made (Section 5.2)

8. Data Retention

• Identification Images: Images used only for identification are not stored on our servers - they are stored locally on your device and temporarily processed by Google Gemini AI
• Contributed Data (opt-in): Contributed images and scan records are retained while your consent is active, reviewed at least every 24 months, and deleted on your request (Section 5)
• Identification Reports: Reports you submit contain no free text and no name, email, or account identifier. They are retained while useful for improving identification accuracy, and are included in your export and removed by your deletion request
• Deletion Audit Records: Anonymized records of performed deletions are retained for up to 24 months, then automatically expire
• Google AI Processing: Stamp images sent to Google Gemini AI for processing are processed temporarily and are NOT stored for long-term storage by Google according to their data retention policies, over which we have no control
• Usage Data: Analytics event data is retained by Google Analytics for no longer than 14 months (the property's data-retention setting), aggregated reports may be kept longer in anonymized form
• Subscription Data: Subscription and payment information is managed by RevenueCat and app store providers (Apple and Google)
• Local Data: All collection history and images are stored locally on your device and can be deleted through the app at any time

9. Your Rights and Choices

You have the following rights regarding your personal information:

• Access: Request information about data we have collected. For contributed data, use "Export my contributed data" in Settings for an immediate, complete copy
• Deletion: Request deletion of your personal information. For contributed data, use "Delete contributed data" in Settings — it takes effect immediately, no email required. See our data deletion instructions
• Correction: Request correction of inaccurate information
• Data Portability: Request a copy of your data in a portable format. The in-app export provides contributed data as a standard ZIP archive with JSON records and image files
• Withdraw Consent: Turn off "Contribute scan photos" in Settings at any time to stop future contributions, or "Allow catalog publication" on its own to stop publication while continuing to contribute privately — withdrawal is as easy as consenting
• Restriction: Ask us to restrict processing of your personal information while a request of yours is being resolved
• Objection: Object to processing we base on legitimate interests (for example, analytics) — we will stop unless we can show compelling legitimate grounds
• Opt-out: Opt-out of certain data collection practices
• Complaint: If you are in the EU/EEA, you have the right to lodge a complaint with your national data protection authority or the Lithuanian State Data Protection Inspectorate (VDAI)

10. Children's Privacy

Our app is not directed to children under 13 years of age. We do not knowingly collect personal information from children under 13. The contributed reference database (Section 5) additionally requires the user to be old enough to consent to data processing in their country (16 in most EU member states, or the lower age their member state has set); it is not offered to users below that age. If you believe we have collected information from a child under the applicable age, please contact us immediately and we will delete it.

11. International Data Transfers

Your information may be transferred to and processed in countries other than your own. Contributed data (Section 5) is stored in Google Cloud infrastructure (see Section 12); Google LLC participates in the EU-U.S. Data Privacy Framework and provides Standard Contractual Clauses for transfers of European data. We ensure appropriate safeguards are in place to protect your data during such transfers.

12. Data Processors

We use the following processors for contributed data and identification reports, acting on our documented instructions:

• Google Cloud / Firebase (Google LLC and Google Ireland Ltd.): Server infrastructure, database (Cloud Firestore), and file storage (Cloud Storage) for contributed data, in the us-central1 region, under the Google Cloud Data Processing Addendum
• RevenueCat, Inc. (United States): Subscription status and purchase records needed to unlock premium features, under RevenueCat's Data Processing Agreement (transfers covered by the EU-U.S. Data Privacy Framework / Standard Contractual Clauses)
• Google Analytics for Firebase (Google LLC / Google Ireland Ltd.): App usage analytics and ad-conversion measurement for our own campaigns, subject to your consent choices where consent applies (see Section 6.3)
• eBay Inc. (Browse API): When you view the "Live on eBay" card, the app sends the identified stamp's name, year and country — never your identity, photo, or device data — to eBay to fetch current listings. This is not personal data; it is listed here for completeness

13. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. We will notify you of any material changes by posting the new policy in the app and updating the "Last Updated" date above. If a change materially affects the contributed reference database consent, contribution stops until you agree to the updated terms.

14. Contact Information

15. Legal Basis for Processing (GDPR)

If you are in the European Union, our legal basis for processing your personal information includes:

• Consent: For optional features — the contributed reference database (Sections 4 and 5), identification reports you choose to submit, and analytics where consent applies
• Contract: For providing our services to you, including processing your images for identification when you request a scan
• Legitimate Interest: For improving our app and preventing fraud
• Legal Obligation: For compliance with applicable laws

No automated decisions with legal effect: the app's AI identifications and valuations are informational estimates for you to review. We make no automated decisions about you that produce legal or similarly significant effects (GDPR Art. 22), and we do not profile you.

16. Limitation of Liability

Liability that cannot be excluded: Nothing in this Privacy Policy excludes or limits liability that cannot lawfully be excluded or limited, including liability for death or personal injury caused by negligence, for fraud or fraudulent misrepresentation, and for gross negligence or intentional misconduct. If you are a consumer resident in the European Union, the EEA, or the United Kingdom, your mandatory statutory rights — including your rights under the GDPR — are unaffected by the limitations above, which apply only to the extent permitted by the consumer law of your country of residence.

17. Indemnification

18. Governing Law and Jurisdiction

This Privacy Policy and any disputes arising out of or related to it shall be governed by the laws of Lithuania, without regard to conflict of law principles. Any legal action or proceeding shall be brought exclusively in the courts of Lithuania, and you consent to the jurisdiction of such courts. Nothing in this section limits the rights EU/EEA residents have under the GDPR, including the right to complain to a supervisory authority.

19. California Privacy Rights (CCPA)

If you are a California resident, you have additional rights under the California Consumer Privacy Act, including the right to know what personal information we collect and how it's used, the right to delete personal information, and the right to opt-out of the sale of personal information. We do not sell personal information. However, these rights are subject to the limitations and disclaimers set forth in this Privacy Policy.