Privacy Policy

Effective Date: January 16, 2026

1. Data We Collect

We believe in transparency. Here is the exact list of data we store on our servers (located in the EU/US):

A. Account Data

• Identity: Email address, pseudonym (username), and a secure hash of your password.
• Profile (Optional): University and Degree program (if you choose to provide them).
• Gamification: Your current level, XP, and streak status.

B. Learning Data (Sync)

To enable synchronization across devices, we store:

• Flashcards: The text and formatting of your cards (Front/Back content).
• Media: Images or audio attached to cards are stored in our secure object storage (Cloudflare R2).
• Scheduling: Mathematical parameters (FSRS weights, stability, difficulty) and review history logs.

C. Subscription Data

• We store the Transaction ID provided by Apple/Google to verify your Pro status.
• We DO NOT store your credit card information or billing address. All payments are processed entirely by Apple (App Store) or Google (Play Store).

2. Third-Party Services

We use the following trusted third-party providers:

• Cloudflare R2: For encrypted storage of media files (images/audio).
• Apple / Google: For payment processing.

3. Data Deletion

You can request the deletion of your account and all associated data at any time by contacting us (info@checkst.app) or using the "Delete Account" option within the app.

4. Contact

If you have questions about this policy, please contact us at:

Magnus Ohle
Email: info@checkst.app