Last updated: 16 July 2026

This Privacy Policy explains how Sean, an independent developer (“Developer,” “we,” “us,” or “our”), handles information in connection with the mobile application Crystal Keeper: Stone Journal (“Crystal Keeper” or the “App”). We respect your privacy and aim to collect as little personal information as possible while still providing the App’s features.

This Privacy Policy should be read together with our Terms of Use. By using the App, you acknowledge the practices described here.

1. Who We Are

The App is operated by an individual developer (Sean). For any privacy questions or requests, contact us at [email protected].

2. A Note on Local-First Design

Crystal Keeper is designed to be local-first. Your crystal collection and the information you record about each crystal are stored on your device, not on our servers. We do not currently operate user accounts or a central database of your collection.

The main exceptions are AI identification and subscription verification. When you choose to identify a crystal, a compressed copy of the photo you submit is sent through our server to a third-party AI service for processing (see Section 4). Our server also processes a random device identifier, your Internet Protocol (IP) address, limited service data, and—if you have a Pro subscription—Apple-signed subscription information to verify access, apply the correct allowance, protect the service from abuse, and keep it functioning.

3. Information We Collect

We keep data collection minimal. Depending on how you use the App, the following may be involved:

• Photos and images you submit. When you actively request AI identification, the App creates a compressed copy of the selected image and uploads it for processing as described in Section 4. Photos that you only save in your collection remain on your device.
• Crystal information you enter. Notes, names, and other details you record about your crystals. This is stored locally on your device.
• Camera and photo library access. With your permission, the App accesses your camera and/or the photos you select so you can capture, choose, and save images. You can change these permissions at any time in your device settings.
• Anonymous device identifier. The App generates a random identifier and stores it in the Apple Keychain. It may survive deletion and reinstallation of the App. The identifier is sent with AI-identification and quota-status requests and is used to apply per-device usage limits and prevent abuse. On our server, counters use a one-way keyed hash of this identifier rather than storing the original identifier as the counter key. It is not Apple's advertising identifier and is not used for advertising or cross-app tracking.
• Subscription verification data. If the App finds an eligible Pro purchase, it sends the Apple-signed StoreKit transaction to our server. The server uses limited purchase and subscription information contained in that transaction—such as the transaction identifier, product identifier, App Store environment, and entitlement status—to ask Apple's App Store Server API whether Pro access is currently active or in a billing grace period. This is used only to provide Pro features and enforce the applicable service allowance. We do not receive your payment card, billing address, or other payment method details.
• IP address and service data. When the App connects to our server, the server necessarily receives your IP address. We use it for short-term rate limiting, security, and abuse prevention. We may also process request timestamps, response status, processing duration, approximate request size, rate-limit events, and the suggested crystal name for operational troubleshooting.
• Apple diagnostics. Apple may provide us with aggregated crash and usage statistics through App Store Connect if you enable sharing in your device settings. Apple controls that collection under its own privacy terms.

We do not collect your name, email, contacts, precise location, or payment information through the App itself. Any purchases are handled by Apple, and we do not receive your payment details.

4. AI Image Identification and Third-Party Processing

This is the most important disclosure in this policy.