Privacy Policy for PrefixBlocker
Last updated: May 2026
This Privacy Policy describes how the Android application PrefixBlocker ("the Application"), developed by Laurent Castell and published through KSTL.fr ("the Publisher"), handles user information.
1. No Data Collection or Transmission
PrefixBlocker does not collect, transmit, sell, share, or otherwise disclose any personal data or personally identifiable information.
The Application does not request the Android INTERNET permission. As a result, no information from your device can be transmitted to the Publisher or to any third party.
The Application does not include advertising SDKs, analytics services, tracking technologies, or marketing tools.
2. Permissions Used by the Application
To provide its core functionality, the Application requires certain Android permissions.
Call Screening Service
The Application uses Android's CallScreeningService API to identify and block incoming calls that match user-defined blocking rules.
The Application does not record calls, access call content, listen to conversations, or transmit call information outside the device.
Contacts Access
The Application may request access to the device's contacts.
Contacts are processed locally on the device only to determine whether an incoming call belongs to a known contact and should be exempt from blocking rules.
Contact information never leaves the device.
3. Local Storage
The Application stores certain information locally on the device, including:
- User-defined blocking rules;
- Contact whitelist information;
- Blocked call history;
- Application settings.
Blocked call history may contain information such as phone numbers and call timestamps. This information is stored exclusively on the device and is never transmitted externally.
4. Data Deletion
Users may delete blocked call history directly from within the Application.
Uninstalling the Application removes all associated locally stored data from the device.
5. Third-Party Services
The Application does not use third-party analytics services, advertising networks, tracking technologies, or external data processing services.
No user information is shared with third parties.
6. Children's Privacy
The Application is not specifically directed toward children under the age of 13.
Because the Application does not collect or transmit personal information, it is designed to minimize privacy risks for all users.
7. Changes to This Privacy Policy
This Privacy Policy may be updated from time to time.
Any updates will be published on this page, and the "Last updated" date will be revised accordingly.
8. Contact
If you have any questions regarding this Privacy Policy or the Application, you may contact:
Laurent Castell
Email: laurent@kstl.fr