Privacy Policy for Period Tracker

Last updated: April 7, 2026

Thank you for using Period Tracker ("the App"). Your privacy is critically important to us — especially given the sensitive nature of menstrual and reproductive health data. This Privacy Policy explains how we handle your information.

1. Our Core Principle

Period Tracker is designed with a privacy-first, zero-server approach. The App works entirely offline. No account is required. No data ever leaves your device. We have no server, so we physically cannot access your information.

2. Information Collection

2.1 Locally Stored Data

The following data is stored only on your device, protected by AES-256 encryption via Android KeyStore, and is never uploaded to any server:

• Period records (start date, end date, cycle length, period length)
• Symptom and mood logs (type, severity, notes)
• Basal body temperature (BBT) entries
• Weight records
• Pregnancy mode data (last menstrual period date)
• App preferences (notification settings, language, theme, lock settings)
• PIN hash and salt (stored encrypted; we never store your actual PIN)

2.2 Information We Do NOT Collect

The App does NOT collect:

• Personal identifying information (name, email, phone number, age, etc.)
• Location data
• Device identifiers or advertising IDs
• Usage analytics or behavioral tracking data
• Photos, contacts, or any other device data
• Any health information beyond what you voluntarily enter

3. On-Device AI Processing

The App's Pro version includes AI-powered cycle insights (smart summaries, daily tips, symptom pattern recognition). This AI processing is handled entirely on your device using Google's ML Kit GenAI (Gemma) technology:

• No cloud processing: Your health data is never sent to any server, cloud service, or external API for AI analysis
• No AI training: Your data is never used to train or improve AI models
• On-device only: The AI model runs locally on your phone's processor
• Not medical advice: AI-generated insights are for general health reference only and do not constitute medical diagnosis or advice

On devices that do not support on-device AI, a rule-based analysis engine provides equivalent insights using statistical templates — no data leaves your device in either case.

4. How We Use Information

All data stored by the App is used exclusively to provide its core features: period tracking, cycle prediction, symptom logging, temperature charting, fertility estimation, AI-powered insights, and notifications. Data never leaves your device.

5. Information Sharing

We do NOT share any user data with third parties. The App contains:

• No advertising SDKs
• No analytics or tracking SDKs
• No social media SDKs
• No data collection or telemetry of any kind

6. Third-Party Services

• Google Play Billing: Used only if you choose to purchase Pro. Google processes the payment; we receive only a confirmation of purchase status. Google's Privacy Policy
• Google ML Kit GenAI: Used for on-device AI processing only. The ML Kit runtime executes locally on your device — no data is sent to Google's servers for inference. ML Kit Terms

7. Data Security

We take extraordinary measures to protect your sensitive health data:

• Database encryption: All data is stored in an AES-256 encrypted database (SQLCipher). The encryption key is protected by Android KeyStore hardware.
• PIN protection: PIN hashes are computed using PBKDF2 with 100,000 iterations — resistant to brute-force attacks.
• Biometric lock: Optional fingerprint/face unlock via Android BiometricPrompt.
• Screenshot protection: The App sets FLAG_SECURE to prevent screenshots and screen recording.
• Encrypted preferences: Sensitive settings (PIN hash, salt) are encrypted before storage.
• No server: We operate zero servers. There is no risk of server-side data breaches.

8. Data Export

Pro users can export all data (periods, symptoms, temperatures, weight) as a CSV file or a PDF health report. Exported files are created locally on your device and shared through your chosen method.

9. Data Retention & Deletion

8.1 Retention Period

All data is stored locally on your device for as long as you use the App. We do not store any data on external servers.

8.2 How to Delete Your Data

You can delete your data at any time:

• Delete individual records: In the history screen, delete individual period records.
• Delete all data: Go to Me > Delete all data to permanently erase all period records, symptoms, temperatures, and preferences.
• Uninstall the App: Removing the App from your device automatically deletes all data.

Once deleted, data cannot be recovered — we keep no backups anywhere.

10. Permissions Explained

Permission	Purpose	Required
Notifications	Period, ovulation, and medication reminders	No
Biometric	Fingerprint/face unlock for app lock	No
Boot Completed	Re-register reminders after device restart	No

All permissions are optional. The App functions fully without any permissions granted.

11. Reproductive Health Data Protection

We recognize that menstrual and reproductive health data is among the most sensitive personal information. Our zero-server architecture means:

• No government or third party can subpoena data from us — we don't have it
• No data breach can expose your health information — it only exists on your device
• You have complete control over your data at all times

12. Children's Privacy

The App is not directed at children under the age of 13, and we do not knowingly collect personal information from children.

13. Changes to This Policy

We may update this Privacy Policy from time to time. Updated policies will be posted on this page with a new "Last updated" date.

14. Contact Us

If you have any questions about this Privacy Policy, please contact us at [email protected].