Quartenson

Privacy Policy

Last updated: May 2026

Quartenson ("we", "us", or "our") builds mobile applications designed for focus, cognitive training, and self-improvement. This Privacy Policy explains what information we collect, how we use it, and what choices you have. We aim to keep things clear and honest — no legal jargon for its own sake.

By using any Quartenson app, you agree to the practices described in this policy. If you have questions, you can reach us at quartenson.support@gmail.com.

1. Information We Collect

Analytics & Usage Data

We use Firebase Analytics to understand how people use our apps. This includes information such as which screens you visit, how long sessions last, general device type, and operating system version. This data is collected in aggregate and is not used to identify you personally.

Crash Reports

We use Firebase Crashlytics to automatically collect crash reports when the app encounters an error. These reports include technical details about the crash (stack traces, device model, OS version) but do not include personal content such as your name or email address.

Account Information (Google Sign-In)

Some features may allow you to sign in with your Google account via Google Sign-In. When you do, we receive your Google account ID, display name, and email address. We use this only to identify your account within the app and to sync your progress or preferences. We do not sell your personal data to advertisers or unrelated third parties.

Advertising

Our apps may display ads through Google AdMob, including rewarded ads. Rewarded advertisements may temporarily unlock premium functionality within the app. AdMob may collect identifiers such as your device's advertising ID to serve relevant ads. You can opt out of personalised advertising through your device settings (Android: Settings → Privacy → Ads; iOS: Settings → Privacy → Apple Advertising). We participate in Google's User Messaging Platform (UMP) to obtain your consent for personalised advertising where required by law (for example, in the European Economic Area).

Subscription & Purchase Data

If you purchase a premium subscription or in-app purchase, the transaction is handled entirely by Google Play. We receive confirmation that a purchase was made (purchase token, subscription status) but we do not receive or store your payment details such as credit card numbers.

2. How We Use Your Information

  • To operate and improve our apps.
  • To diagnose bugs and stability issues via crash reports.
  • To understand usage patterns and prioritise features.
  • To show ads and manage ad consent where applicable.
  • To manage your account and subscription status.

3. Data Sharing

We do not sell your personal data. We share data only with the following service providers as necessary to operate our apps:

  • Google / Firebase – analytics, crash reporting, authentication, and cloud infrastructure.
  • Google AdMob – ad serving and monetisation.
  • Google Play – subscription and billing management.

Each of these providers operates under their own privacy policies and data processing agreements with Google LLC.

4. Data Retention

Analytics and crash data are retained according to Firebase's default retention settings (typically 60 days for detailed event data, longer for aggregated reports). Account data is kept for as long as your account is active. Training statistics and session history are stored locally on your device and are removed when the application data is deleted or when the app is uninstalled. You can request deletion at any time (see below).

5. Your Rights & Choices

  • Opt out of personalised ads – via your device's advertising settings.
  • Withdraw consent – you can change your ad personalisation consent at any time within the app settings (where available).
  • Delete your data you may delete your account directly within the app by going to Settings > Delete Account and confirming the deletion. Deletion is processed immediately. You can also contact us at quartenson.support@gmail.com with the subject "Data Deletion Request". For a summary of what is deleted and what may be retained where required by law, see our Account Deletion page.
  • Access your data – you may request a summary of the personal data we hold about you by emailing us.

If you are in the European Economic Area or the UK, you have additional rights under the GDPR / UK GDPR including the right to object, rectify, or port your data. Contact us to exercise these rights.

6. Account Deletion

Schulte Vision Trainer allows users to delete their account directly within the app. Open the app, go to Settings, select Delete Account, and confirm deletion.

When an account is deleted, the following is removed:

  • User account.
  • Premium status.
  • Subscription verification data.
  • User profile information.

The following may be retained only if required by law: records necessary for tax, fraud prevention, chargeback, or legal compliance.

Training statistics and session history remain local to your device and are removed when the application data is deleted or the app is uninstalled.

7. Children's Privacy

Our apps are intended for general audiences and are not specifically directed toward children. We do not knowingly collect personal data from children. If you believe a child has provided us with personal information, please contact us and we will delete it promptly.

8. Security

We use industry-standard security measures and rely on Google's infrastructure to protect data in transit and at rest. No method of transmission or storage is 100% secure, but we take reasonable steps to safeguard your information.

9. Changes to This Policy

We may update this policy from time to time. When we do, we'll update the "Last updated" date at the top of this page. We encourage you to review the policy periodically. Continued use of our apps after any changes constitutes acceptance of the revised policy.

10. Contact Us

If you have any questions or concerns about this Privacy Policy or how we handle your data, please reach out: