Privacy Policy
Plain-language summary: Krin is built on the principle of collecting as little as possible. You never need to provide your name or email to use the app. We don't sell your data. We don't show you ads. Your homework stays your business.
1. Who we are
Krin ("krin.", "we", "us", or "our") is an AI-powered homework organization app for teens aged 13–18, operated by Krin App Inc. This Privacy Policy explains how we handle information when you use the Krin mobile application or visit krinapp.com (collectively, the "Service").
If you have questions, contact us at privacy@krinapp.com.
2. Information we collect
Anonymous account identifier
When you first open Krin, we create an anonymous account using Supabase's anonymous authentication. This generates a random user ID. No email address, name, phone number, or any personally identifiable information is required.
Task data you enter
When you add assignments by typing, pasting, or describing them, we store that task data (title, subject, due date, time estimate) in your account on Supabase servers so it persists across sessions. This data is associated only with your anonymous user ID — not with any real-world identity.
Photos you take
When you snap a photo to capture an assignment, that image is streamed directly to our AI processing service (Anthropic Claude API via a Supabase Edge Function) to extract task information. Photos are never stored on our servers. The image is processed in memory and discarded immediately after parsing. We do not retain, train on, or share your photos.
Subscription and payment information
If you subscribe to Krin Premium, payments are handled by RevenueCat and the App Store (Apple) or Google Play. We never see or store your payment card details. RevenueCat provides us with a subscription status (active/expired) and a pseudonymous subscriber ID. See RevenueCat's privacy policy.
Analytics
We use PostHog to understand how people use Krin (e.g., which screens are visited, where users drop off). PostHog is configured to never collect raw date-of-birth. If you complete onboarding and provide your birth year, we derive only an approximate age bucket (e.g., "14–15") for aggregate reporting and do not store your actual birthday beyond the session.
Error reporting
We use Sentry to capture app crashes and errors automatically. Sentry may receive device type, OS version, and a stack trace, but is configured to exclude personally identifiable information.
Push notifications
If you grant notification permissions, Expo Push Notifications generates a push token for your device. This token is stored in your account to deliver homework reminders. It is not shared with advertisers.
3. How we use information
- To provide and improve the Krin app and its features.
- To sync your tasks across app sessions.
- To send push notification reminders you have configured.
- To understand aggregate usage patterns and improve the product.
- To diagnose and fix technical errors.
We do not use your information to show you ads, profile you for marketing, or sell to third parties.
4. Children and teens (under 18)
Krin is designed for users aged 13 and older. We do not knowingly collect personally identifiable information from children under 13. If you are under 13, please do not use Krin.
Because Krin uses anonymous authentication, we do not collect verifiable parental consent information. We encourage parents to review this policy with their teens and contact us at privacy@krinapp.com with any concerns.
5. Data sharing
We share data only with the service providers necessary to operate Krin:
- Supabase — database and authentication (servers in the United States).
- Anthropic — AI processing of photos you submit for parsing. Images are not retained by Anthropic beyond the API request.
- RevenueCat — subscription management.
- PostHog — product analytics (anonymized).
- Sentry — error reporting.
- Expo / Apple / Google — push notification delivery.
We do not sell, rent, or broker your data to any third party.
6. Data retention and deletion
Your task data is retained as long as your anonymous account exists. You can permanently delete your account and all associated data at any time from the You → Delete Account screen in the app. Deletion is immediate and irreversible.
Analytics events in PostHog and crash reports in Sentry may be retained for up to 12 months for product improvement purposes.
7. Security
All data is transmitted over HTTPS/TLS. Your task data is stored in Supabase with Row Level Security (RLS) policies that ensure each user can only access their own data. Photos are processed in ephemeral memory and never written to disk.
8. Your rights
Depending on where you live, you may have rights to access, correct, or delete your personal data. Since Krin stores data anonymously, the most effective way to exercise these rights is to delete your account in-app, which removes all data immediately. For other requests, contact privacy@krinapp.com.
9. Changes to this policy
We may update this Privacy Policy from time to time. When we do, we'll update the "Last updated" date at the top of this page and, for material changes, notify you via an in-app message.
Contact us
Questions about this policy? Email privacy@krinapp.com. We aim to respond within 5 business days.