Privacy Policy

HankoStamp ("we", "our", or "us") is a solo-developed iOS app. This policy explains what data we collect, why, and how it is used.

1. Data we collect

Photos you choose to process. When you create a stamp, the photo you select is sent to OpenAI's API to generate the stamp layers. We do not store the original photo on our servers. OpenAI processes the image and returns the result; OpenAI does not use API-submitted images to train its models (see OpenAI's privacy policy at openai.com/policies/privacy-policy).

Stamp data. If you choose to share a stamp, the composite image and layer images are uploaded to our cloud storage (Supabase) so others can collect it. Shared stamps are public.

Account information. If you sign in with Google, we receive your Google account name and email address. Your email is stored securely and used only for account identification.

Location data. If your photo contains GPS metadata (EXIF), that location is stored locally on your device and used to place a pin on your Eki Book map. Location data is not sent to our servers unless you share a stamp, in which case the stamp's location is included.

Analytics. We collect anonymous usage events (e.g. "stamp created", "stamp shared") via PostHog. Events are not linked to your identity unless you sign in. No personal data is included in analytics events.

2. Third-party services

HankoStamp uses the following third-party services:

• OpenAI — Photo processing and stamp generation. Photos you submit are sent to OpenAI's API. OpenAI's privacy policy applies to this data.
• Supabase — Cloud storage and authentication for shared stamps and user accounts.
• PostHog — Anonymous product analytics.
• Google Sign-In — Optional authentication. Only used if you choose to sign in.

3. Data storage and retention

Your stamps and Eki Book are stored locally on your device. Shared stamps are stored on our servers until you delete them. Account data is retained until you delete your account.

4. Your rights

You can delete your shared stamps and account at any time from within the app. To request deletion of all data associated with your account, email us at hanko@nichescout.pro.

5. Children's privacy

HankoStamp is not directed at children under 13. We do not knowingly collect personal data from children under 13.

6. Changes to this policy

We may update this policy from time to time. The effective date at the top of this page will reflect the most recent revision.

7. Contact

Questions about this policy? Email us at hanko@nichescout.pro.