Effective date: April 21, 2026

1. Introduction

This Privacy Policy explains how the Yellow Butterfly service handles personal data when you use our application or website. We follow the principle of data minimisation: we do not collect or store personal data on our servers, and your test results stay on your device.

2. Data Stored Locally on Your Device

When you use the application, the following data is stored locally on your device only:

  • Test results and their interpretation;
  • Symptoms you choose to log;
  • Application settings.

This data never leaves your device unless you explicitly choose to export or share it.

3. Data You Provide Voluntarily

If you contact us through our Telegram support bot, the messages you send are processed within Telegram’s infrastructure under Telegram’s own terms. We use those messages only to respond to your request and do not retain them outside Telegram.

If you order test strips through our partners, the partner — not the Yellow Butterfly service — handles the data necessary to fulfil the order. Please refer to that partner’s privacy policy for details.

4. Cookies and Website Analytics

Our website may use cookies and aggregated, anonymised analytics to understand general usage patterns. No personally identifiable information is collected through these means. You can disable cookies through your browser settings.

5. Data Sharing

We do not sell, rent, or transfer personal data. Because we do not collect personal data on our servers in the first place, there is nothing to share with third parties.

6. Children

The service is not directed at persons under the age of 16. We do not knowingly collect data from children. If a parent or guardian believes a child has provided personal data through us, please contact us and we will assist.

7. Security

The data stored on your device is protected by your device’s operating system. We recommend using a screen lock and keeping your device’s software up to date.

8. Changes to This Policy

We may update this Privacy Policy from time to time. The current version is always available on this page. Continued use of the service after changes are posted constitutes acceptance of the updated Policy.

9. Contact

If you have questions about this Privacy Policy, please contact us via the Telegram bot: @yb_sup_bot (https://t.me/yb_sup_bot).