US Privacy Policy

Privacy Policy for users in the United States

Last updated: September 24, 2026

DeepChinese ("we", "us") is a Chinese character learning app. It is designed to be local-first: your learning data is created and kept on your own device, and an account is entirely optional. This policy explains what information is involved when you use DeepChinese in the United States, including your rights under California law (CCPA/CPRA) and other applicable US state privacy laws.

1. Information involved

• On-device learning data. Your favorites, flashcard lists, study settings, reminders and progress are stored locally on your device (for example via on-device app storage). If you never create an account, we do not receive or store this data on our servers.
• Account information (only if you sign in). Your e-mail address, which we use to send a one-time sign-in code — there is no password — or the identifier from Google/Apple sign-in where offered, plus an optional display name and account timestamps. CCPA category: identifiers.
• Synced study data (only if you sign in). Copies of your favorites, spaced-repetition progress, Deep Drill and HSK-practice results, flashcard lists and three preferences (theme, app language, character style), plus a random per-install device identifier used to merge changes made offline on different devices. Reminder times, notification consent, per-deck study options and session history are never synced. CCPA category: internet or electronic network activity information.
• Support messages. If you contact us through the in-app Contact / Help section, we receive the contents of your message and any contact details you provide, solely to respond.
• Purchases. Pro subscriptions and lifetime purchases are processed by the Apple App Store, Google Play, or our payment provider acting on the store's behalf. We do not see or store your full payment details; the stores share only what is needed to unlock your purchase (such as purchase status), which we mirror against your account so Pro follows you between devices. CCPA categories: commercial information and financial information.
• Product analytics. Usage events — and, when something goes wrong in the app, error and crash reports — are sent to our product-analytics provider, which processes them on European infrastructure, so we can see which features are used and find defects. This is anonymous by default; if you sign in, events may be linked to your account identifier, and that link is removed when you delete your account.
• Website language preference, stored in your browser's local storage when you visit deepchinese.nl.

2. How we use information

• To provide and operate the app's features (stories, search, flashcards, reminders).
• To back up and sync your progress between your devices, when you ask us to by signing in.
• To unlock Pro features you purchased and restore them.
• To respond to support requests.
• To understand which features are used, in aggregate.
• To comply with legal obligations.

3. What we do not do

• We do not sell your personal information.
• We do not share personal information for cross-context behavioral advertising.
• We do not track you across other apps or websites for advertising.
• We show no third-party ads in the app.
• We do not require an account, and we do not collect data about you before you choose to create one.

4. Where your data is stored

The account backend — sign-in and the study-data database — is hosted in Switzerland by a professional hosting provider. Everything that is not part of your account stays on your device.

5. Service providers

We disclose the information above to a short list of service-provider categories, each acting on our instructions: a hosting provider (account sign-in and the study database, in Switzerland), a payment provider (purchase validation), an analytics provider (usage events and error/crash reports, on European infrastructure), an e-mail provider (sign-in codes and support), and the App Store / Google Play, which are independent businesses that keep your store account and purchase history under their own policies. If you need to know which specific company handles what, ask us at the address in §11 and we will tell you.

6. Your California privacy rights

If you are a California resident, the CCPA/CPRA gives you the right to:

• Know what personal information is collected, used and disclosed about you.
• Delete personal information we hold about you.
• Correct inaccurate personal information.
• Opt out of the sale or sharing of personal information (we do not sell or share, so there is nothing to opt out of).
• Limit use of sensitive personal information (we collect none).
• Non-discrimination for exercising these rights.

Because learning data stays on your device by default, you can delete it at any time yourself by clearing the app's storage or uninstalling the app through your device's settings. If you created an account, you can delete it in the app under Settings → Account → Delete account, or from the web using our account deletion page, which lists what we delete, what we keep and for how long. For any other request (for example about a support message you sent), email us atprivacy@deepchinese.nl. We will verify your request and respond within the time required by law. You may use an authorized agent as permitted by law.

7. Other US states

If you live in a state with its own privacy law (such as Colorado, Connecticut, Utah, Virginia or others), you have comparable rights to access, correct, delete and opt out of certain processing. The same contact above applies.

8. Children

DeepChinese is not directed at children under 13, and we do not knowingly collect personal information from children under 13. If you believe a child has sent us personal information, contact us and we will delete it.

9. Security and retention

On-device data is protected by your device's own security (such as screen lock and encryption). Account data travels only over TLS, and row-level security in the database means an authenticated user can read and write only their own rows; signed-out clients can read none of them. Support messages are kept only as long as needed to handle your request. Account data is deleted together with your account. Purchase records are retained as required for accounting, tax and legal purposes. Encrypted database backups are overwritten as backup cycles expire, and we do not restore personal data from them after a deletion.

10. Changes to this policy

If we change this policy, we will post the updated version here with a new "Last updated" date. Material changes will be highlighted in the app where appropriate.

11. Contact

Questions or privacy requests:privacy@deepchinese.nl.

Visiting from Europe? Read ourEU Privacy Policy instead.