Libellus Potionis

Libellus Potionis is a privacy-conscious, free, open source and ad-free drinking logging tool. It helps you monitor, moderate and manage your drinking completely offline. It does not require any intrusive permissions-no camera, microphone, or positioning-and requires no network access at all to operate.

main function

·Smart Recording: Customize your own drink or choose from internationally accepted presets. It can be recorded immediately, or it can be re-recorded and accurately corrected afterwards. ·Set multiple limits at the same time: Set three limits in parallel-a daily limit (grams of pure alcohol), a rolling 7-day weekly limit (grams), and a maximum number of days per week. Progress bars let you know the situation in real time. ·Blood alcohol concentration (BAC) estimation: By inputting body weight, a real-time estimate can be obtained based on the recognized Widmark formula. ·Consultation report: Generate a clear, well-organized two-page PDF report specifically designed for consultation and tutoring appointments, summarizing your habits in a statistical manner. Data portability: Export the complete dataset to a standard CSV file for external processing (such as in LibreOffice Calc), or create secure JSON backups to migrate data between devices. ·Fine adjustments: Customize the "start of the day" time so that late night drinks count into the correct night; and set a custom evaluation start date to start over cleanly.

A complete user guide is provided within the app.

privacy and security

Libellus Potionis is built around absolute data sovereignty and strict data minimization. It runs in a minimum privilege configuration and completely excludes network access, so your personal data never leaves the device. Your data is held in the app's private storage and is protected at rest by Android device storage encryption and application sandboxed. Optional biometric fingerprint lock prevents unauthorized physical access. This offline-first approach eliminates tracking, cloud synchronization and external data leaks.

compatibility

Apps can run on Android 11 (API 30) and later. A completely independent language selector within the application can be used on all supported versions, regardless of the system's per-application language selector.

open source

Libellus Potionis is free software distributed under the GNU General Public License v3 (or later). The source code is documented in textbook-level standards and can be obtained in the Specification Code Warehouse: codeberg.org/godisch/potillus/