Privacy Policy for Cephalo

Last Updated: July 2026

Introduction

Your privacy is critically important to us. Cephalo is designed with privacy as a fundamental principle. This Privacy Policy explains how we handle your information when you use our headache tracking app.

Our Core Privacy Principles

  1. Your data stays yours - We don't have access to your health data
  2. No third-party tracking - No advertising trackers, no analytics companies, no data brokers
  3. No ads - We don't show advertisements or sell data to advertisers
  4. Local first - Data is stored on your device by default
  5. Optional sync - Cloud features are entirely optional

Information We DON'T Collect

Cephalo does NOT:

  • Collect your headache diary, notes, or health data
  • Store or track your location
  • Access your contacts
  • Send your health data to any servers
  • Use third-party analytics or advertising trackers
  • Share data with third parties
  • Display advertisements

App Reliability Statistics (First-Party)

To know whether Cephalo works — how many devices run it, whether an update broke something, whether people who see the upgrade screen find it useful — the app sends a small number of technical events to our own server (operated by Iterica B.V., no third parties involved):

  • What is sent: app lifecycle events (install, update, re-install), session start/end, and which in-app upgrade screens were shown — together with the app version and a random device identifier
  • The identifier is a random value generated on your device. It is not your name, email, phone number, or Apple ID, and it is not the advertising identifier (IDFA). It exists so we can count devices and re-installs instead of inflating every launch into a "new user"
  • What is never included: your headache entries, notes, symptoms, medication, health data, location, or anything you type into the app
  • These statistics are never sold, shared, or combined with data from other companies, and are not used for advertising

Data Storage and Processing

Local Storage

  • All headache entries are stored locally on your device
  • Data is stored using Apple's Core Data framework
  • Data remains on your device unless you explicitly enable iCloud sync
  • Deleting the app removes all locally stored data

Optional iCloud Sync

If you choose to enable iCloud sync:

  • Data is stored in YOUR personal iCloud account
  • Synchronization occurs through Apple's CloudKit framework
  • We cannot access your iCloud data
  • Data is encrypted in transit and at rest by Apple
  • You can disable sync at any time in Settings

Optional Private Federated Learning

Private federated learning is an optional, off-by-default way for Cephalo users to improve headache pattern recognition together — without anyone sharing their personal data.

How it works:

  • Your phone learns from your patterns locally, on your device
  • It creates anonymous "lessons learned" (technically: model updates), scrambled with mathematical noise so they cannot be traced back to you
  • These updates are encrypted so that even our servers can only ever see the combined result of a large group — never an individual contribution
  • Everyone who participates receives the improved pattern recognition back

Never shared:

  • Your headache episodes, medications, triggers, or symptoms
  • Your location or health data
  • Any personal or device-identifying information — participation is anonymous

Your control:

  • Off by default — participation requires your explicit opt-in
  • Pause or stop participating at any time in Settings
  • Delete all private federated learning data from your device instantly
  • A privacy budget shown in the app limits how much can ever be learned from any one person (differential privacy, the same kind of technique Apple uses to improve iOS without reading anyone's data)

Apple Health Integration (Optional)

If you choose to enable Apple Health:

  • The app can read: sleep data, heart rate, HRV, oxygen levels, menstrual data
  • The app can write: headache episode records
  • All Health data stays within Apple's secure Health framework
  • You control permissions through iOS Settings
  • Integration can be disabled at any time

Weather Data (Cephalo Plus Feature)

If you have Cephalo Plus and enable weather correlation:

  • The app requests your location ONLY when you log a headache episode
  • Location permission is requested when you first enable weather tracking in Settings
  • Location is used solely to fetch weather data from Apple WeatherKit
  • Weather data collected includes:
    • Temperature (Celsius)
    • Barometric pressure (millibars) and pressure trends
    • Humidity (percentage)
    • Wind speed (km/h)
    • UV index
    • Weather conditions (clear, cloudy, rain, etc.)
  • Your location coordinates are NOT stored in the app - only the weather data is saved
  • Location data is sent to Apple's WeatherKit service to retrieve weather information
  • Your health data NEVER leaves your device - only location is shared with Apple for weather
  • We (Iterica B.V.) do not receive or have access to your location data
  • You can disable weather tracking in Settings at any time
  • Location permission can be revoked in iOS Settings → Privacy → Location Services
  • Weather tracking requires a Cephalo Plus subscription

Apple WeatherKit Privacy:

  • WeatherKit is Apple's privacy-focused weather service
  • Apple processes location data according to their privacy policy
  • No third-party weather services or APIs are used
  • Weather attribution " Weather" is displayed as required by Apple
  • WeatherKit data is processed on-device when possible

Data You Create

Headache Entries Include:

  • Date and time of episodes
  • Pain intensity and location
  • Symptoms and characteristics
  • Medications taken
  • Personal notes
  • Weather conditions (if location permission is granted)
  • Health context (if Apple Health is enabled)

Data Control

You can:

  • View all your data within the app
  • Export data as JSON, CSV, or PDF
  • Delete individual entries
  • Delete all data at once
  • Disable cloud sync anytime
  • Remove Apple Health permissions

Data Sharing

You Control Sharing

  • Export features let YOU share data with healthcare providers
  • PDF reports can be generated for medical consultations
  • No automatic sharing occurs

No Third-Party Access

  • We don't sell, trade, or transfer your data
  • No analytics companies have access
  • No advertising networks are used
  • No social media integration

Children's Privacy

  • The app does not knowingly collect data from children under 13 (or 16 in EU)
  • The app is intended for users who can provide informed consent
  • Parents/guardians should supervise minors' use
  • If we learn we have collected data from a child, we will delete it

Cookies and Web Analytics

On our website (cephalo.app):

  • We do not use cookies or tracking technologies
  • We do not use Google Analytics or similar services
  • We do not collect visitor data
  • The website is purely informational

Data Retention

  • App data: Retained until you delete it
  • iCloud data: Follows Apple's retention policies
  • App reliability statistics: retained on our server for up to 24 months, then deleted or fully aggregated
  • Your health data is never on our servers, so there is nothing for us to retain or recover

Your Rights

You have the right to:

  • Access your data (through the app)
  • Correct your data (by editing entries)
  • Delete your data (individually or all at once)
  • Export your data (multiple formats available)
  • Disable cloud features
  • Uninstall the app and remove all local data

European Users (GDPR)

For users in the European Union:

  • Legal basis: Consent for optional features (iCloud sync, Apple Health, private federated learning); legitimate interest for the minimal first-party app reliability statistics described above
  • Data controller for your health data: You (the user) — it never reaches us
  • Data controller for app reliability statistics: Iterica B.V.
  • Private federated learning: processes only anonymous, aggregated model updates that cannot be linked to a person; no personal data reaches Iterica B.V.
  • Right to portability: Export features provided
  • Right to erasure: Delete options in Settings
  • No automated decision-making or profiling; risk predictions are computed on your device only

Data Protection Officer

For privacy-related questions, you can contact us at:

  • Company: Iterica B.V.
  • Email: privacy@cephalo.app
  • Address:

Legal Basis for Processing

We process your personal data on the following legal grounds:

  • Consent: You explicitly choose to use the app and its features
  • Legitimate Interest: To provide and improve the app functionality
  • Legal Obligation: To comply with applicable laws and regulations

Data Breach Notification

In the unlikely event of a data breach:

  • Local data: We cannot detect breaches of data stored only on your device
  • iCloud data: Apple is responsible for notifying users of iCloud breaches
  • We will notify users via app update if we become aware of any security issues

Complaints

If you have concerns about how your data is handled:

  • Contact us first at privacy@cephalo.app
  • You have the right to lodge a complaint with your local data protection authority
  • Netherlands residents can contact the Autoriteit Persoonsgegevens (Dutch DPA)
  • EU residents can contact their national data protection authority

Summary

We don't want your data. We can't see your data. Your data stays on your device or in your personal iCloud account. You have complete control.

By using Cephalo, you acknowledge that you have read and understood this Privacy Policy.