Privacy Policy

Summary

Caffeine Ceiling is built to stay on your device. There is no account, no sign-in, and no app server. Your caffeine logs, drink presets, corrections, daily limits, and settings live locally on your iPhone. Because we have no servers for your data, there is nothing for us to upload, read, or sell.

Data Collection

Caffeine Ceiling stores all of your data locally on your device. Your caffeine log, the drinks and presets you create, any corrections you make to a drink's caffeine amount, your daily limit, your sleep-safe threshold, your half-life setting, and your preferences are kept on your device and are not transmitted to us. There are no accounts and no cloud accounts to manage. In a future version you may optionally enable Apple's private iCloud sync to move your own data between your own devices; version 1 keeps everything local to the device.

Apple Health (HealthKit)

Caffeine Ceiling can work with Apple Health, but only if you grant permission, and only for the specific data described below. Health access is entirely optional. The app is fully functional without it.

- **Writing caffeine to Health.** With your explicit permission, the app writes each caffeine entry you log to Apple Health as a Dietary Caffeine sample. This keeps the number consistent with your overall health record so other apps you trust can see a complete picture. - **Reading sleep and body weight.** For users who have unlocked the app and choose to opt in, the app can read your Sleep and Body Weight samples from Apple Health to personalize your estimates (for example, to inform the daily limit and the sleep-safe threshold). You decide whether to allow this.

HealthKit data is processed entirely on your device. It is never transmitted off your device, never sent to us, never shared with any third party, and never sold. We do not use Health data for advertising. You can change or revoke Health permissions at any time in the iOS Health app or in Settings, and the app will keep working without them.

Anonymous Analytics

Caffeine Ceiling uses a privacy-respecting analytics service (Mixpanel) to collect anonymous, aggregated usage information so we can understand which features are used and where people get stuck, and improve the app. Analytics events are tied only to a random, app-generated identifier:

- **Usage events**: which screens are viewed and which features are used - **Device information**: app version, device type, OS version

This identifier is not linked to your name, email, or any account, because there is no account. No personal data and no health data is ever sent to analytics. We do not collect your caffeine log, your Health data, or any identifying information through analytics, and Mixpanel does not use advertising identifiers (IDFA). No data is shared with third parties for advertising purposes.

You can learn more about Mixpanel's privacy practices at mixpanel.com/legal/privacy-policy.

In-App Purchases

Caffeine Ceiling offers a single one-time unlock (a non-consumable in-app purchase). The purchase is handled entirely by Apple through the App Store using StoreKit. We never see or store your payment information.

What We Do Not Do

We do not track you across other apps or websites. We show no ads. We do not work with data brokers. We do not sell your data. We have no server that holds your caffeine log or your Health data.

A Note on Estimates

Caffeine Ceiling presents a model of how much caffeine is in your system over time, based on a pharmacokinetic estimate with a half-life you can adjust. The numbers are an estimate, not medical advice. This is informational, not diagnostic.

Contact

If you have questions about this privacy policy, contact us at support@9592.tech.