Billings: Cycle Tracker

Billings is the app for those who want to track their fertility and menstrual cycle health while faithfully following the Billings Ovulation Method.

Developed to offer a modern, secure, and completely offline experience, the app allows you to manage your sensitive data with maximum confidentiality, without the need for accounts or external cloud storage.

Main Features:
Daily Tracking: Easily record mucus quality, physical sensations, bleeding, spotting, and intercourse.

Automatic Classification: The app automatically applies the method's official colors (red, green, white, yellow) based on your daily observations.

Peak Day Detection: Integrated algorithm for peak day identification and post-peak count management (3-day rule).

Personalized Forecasts: Receive estimates for upcoming cycles and peak days based on your luteal length and history.

Total Privacy: All data is stored exclusively on your device. No data is shared or sold.

PDF Reports: Generate professional graphs and tables ready for printing or sharing with your doctor (available via in-app purchase).

Pregnancy Management: Dedicated feature to mark and display pregnancy periods within the timeline.

Secure Backup: Export and import your data in JSON format to preserve your cycle history in case you change devices.

Why use Billings?
The app was designed following the Billings Method guidelines, making cycle viewing clear and easy thanks to the integrated color legend:

🔴 Red: Bleeding or spotting.

🟢 Green: Dry day (non-fertile phase).

⬜ White: Presence of mucus or wetness pre-peak.

🟡 Yellow: Mucus or wetness in the post-peak phase.

Technical Details:
Offline-First: The app works perfectly without an internet connection.

Clean Design: Eva Design-based interface for smooth and pleasant navigation.

Note: Billings is a tracking tool and does not replace the advice of a doctor or certified method teacher.