Period Tracker for Flipper Zero

A menstrual cycle tracking application for Flipper Zero. Track cycles for multiple people with predictions, alerts, and statistical learning.

Features

• Multi-user support: Track cycles for multiple people with individual profiles
• Cycle predictions: Next period, PMS, ovulation, and fertile windows
• Event logging: Log period starts and symptoms with a date picker
• Statistical learning: Adjusts cycle predictions based on logged data
• Daily digest: Upcoming events and alerts for all profiles at a glance
• PIN protection: Optional 4-digit PIN with lockout after failed attempts
• Local storage: All data on the SD card; no network or cloud
• CSV format: Event history in human-readable CSV files

Installation

Prerequisites

• Flipper Zero with firmware 1.3.4+ (or any compatible firmware)
• ufbt installed on your computer
• USB cable to connect Flipper

Quick install

1. Install ufbt (if needed):

   python3 -m pip install --upgrade ufbt
   

2. Clone this repository:

   git clone https://github.com/gorshunovr/period_tracker.git
   cd period_tracker
   

3. Build and install:

   ufbt launch
   

The app installs to /ext/apps/Tools/period_tracker.fap on your Flipper.

Manual installation

1. Build: ufbt
2. Copy dist/period_tracker.fap to /ext/apps/Tools/ on the SD card
3. On Flipper: Apps → Tools → Period Tracker

Usage

First run

On first launch you will see a short onboarding screen. Press OK to create your first profile.

Creating a profile

1. Main Menu → Settings → Add New Profile
2. Enter name and details (cycle length, period length, optional health notes)

Logging a period

1. Select a profile from the main menu
2. Choose Log Event → Period Start
3. Pick the date and confirm

Viewing predictions

1. Select a profile → View Predictions
2. See next period, PMS window, ovulation, and fertile window (where applicable)

Daily digest

Shows alerts and upcoming events across all profiles: cycle day, expected symptoms, and upcoming period dates.

PIN protection

1. Main Menu → Settings → PIN Settings
2. Set a 4-digit PIN (required on every launch when enabled)
3. After 4 failed attempts the app locks

To reset a locked PIN: delete /ext/apps_data/period_tracker/pin.txt and pin.locked via qFlipper or the SD card.

Data storage

All data is stored on the SD card at /ext/apps_data/period_tracker/:

File	Purpose
{name}.profile	Profile metadata
{name}.csv	Event log
profiles.idx	Active profile list
settings.txt	App settings
pin.txt	PIN (if enabled)

CSV format

date,event_type,value
2026-07-01,period_start,
2026-07-01,symptom,Cramps
2026-07-02,symptom,Headache

Development

ufbt              # build
ufbt launch       # build and run on device
ufbt format       # format C sources
ufbt lint         # check formatting
ufbt clean        # clean build artifacts

API target: firmware 1.3.4+ (API 86.0+).

Test data

Generate multi-profile sample data (dates relative to today):

cd test_data
python3 generate_test_data.py

Copy the generated .profile, .csv, profiles.idx, and settings.txt files to /ext/apps_data/period_tracker/ on the Flipper SD card. See test_data/README.md.

Limitations

• No background alerts: external apps cannot set RTC alarms; alerts appear when the app is open
• Local only: no network sync
• Monochrome UI: 128×64 text interface
• Storage: keep event history reasonable (under ~1000 entries per profile recommended)

Contributing

1. Fork the repository
2. Create a feature branch
3. Format with ufbt format and test with ufbt launch
4. Open a pull request

License

This project is licensed under the MIT License.

Support

• Issues: GitHub Issues
• Community: forum.flipper.net
• Flipper docs: developer.flipper.net

---

Disclaimer: This app is for informational purposes only and should not be used as a sole method of contraception or medical advice. Always consult healthcare professionals for medical decisions.