Privacy Policy

Last updated: 21 September 2026

The short version: your fasts stay on your device and we never see them. Health data is never sent to us. We do collect anonymous usage analytics and crash reports through Google Firebase, and a push token if you allow notifications — all of it is described below.

1. What stays on your device

FastLine has no account and no sign-in, and we do not run a database of your content. What you create in the app is stored locally on your device using Apple's on-device storage. It is included in your normal encrypted device backup if you use iCloud Backup, which is controlled by Apple, not by us. We never receive a copy.

2. What we collect, and why

We do collect a small amount of anonymous technical data. This section describes all of it.

2a. Usage analytics — Google Analytics for Firebase

FastLine uses Google Analytics for Firebase to understand how the app is used, so we know which features are worth improving. Events record that something happened — a screen was opened, a feature was used, the paywall was shown — and never the content of it. Firebase also collects some data automatically, including an app-instance identifier, device model, operating-system version, and a coarse country-level location derived from your IP address.

2b. Crash reports — Firebase Crashlytics

If the app crashes, Crashlytics sends us an anonymised report containing the stack trace, device model and operating-system version, so we can fix the fault. Apple may separately collect its own crash report, subject to your iOS privacy settings.

2c. Notifications

Reminders are local notifications. Any reminder you enable is scheduled by iOS on your own device, and its text and times never leave your phone.

App announcements are remote. If you allow notifications, FastLine registers with Apple's push service, which issues the app a push token. That token is sent to Google Firebase Cloud Messaging and to our own notification service at engage.puzzpics.com, so we can send occasional messages about the app itself, such as a new feature. That device record contains a random identifier generated by the app for this install — not your Apple ID, and not your device's advertising or vendor identifier — together with the app name, your platform, your iOS and app version, your locale and time-zone identifiers, whether you granted notification permission, and your announcement opt-in choice. The same service records a few fixed events: that a session started, that an announcement was opened, and whether an in-app message was shown, tapped or dismissed. None of it contains your personal content.

2d. Purchases — Apple and RevenueCat

Purchases are processed by Apple through the App Store using StoreKit. We never see your payment details. We use RevenueCat to keep track of whether a purchase is active, so the app knows what to unlock. RevenueCat receives the anonymous identifier and the purchase status, not your name or payment information.

2e. Apple Health — optional, and in both directions

FastLine can connect to Apple Health, and only with your permission. Two separate things can happen, each optional:

Reading: if you turn on the weight trend, FastLine asks permission to read your body-mass entries from Apple Health, to draw a chart inside the app.
Writing: if you turn on Health logging, FastLine asks permission to write a completed fast to Apple Health as a workout, so you can review it alongside your other health data. Short fasts are not written.

Both happen on your device, between FastLine and Apple Health. Your health data is never sent to us, to Firebase, or to any other third party, and it is never included in analytics. You can revoke either permission at any time in Settings › Health › FastLine.

2f. Our other apps

FastLine can show a small suggestion for another app we make. To avoid suggesting something you already have, the app asks iOS whether that specific app of ours is installed. This check happens entirely on your device, and the result is not sent anywhere.

3. Service providers

FastLine relies on the following third parties, each of which processes data under its own terms:

Google — Firebase (Analytics, Crashlytics, Cloud Messaging): anonymous usage events, crash reports, and delivery of announcement notifications. Firebase privacy
Apple (App Store, StoreKit, push delivery): purchases and notification delivery. Apple privacy
RevenueCat: purchase and entitlement status. RevenueCat privacy
Our own notification service (engage.puzzpics.com, operated by us): the device record and fixed events described above.

4. What we never do

There are no ads and no advertising SDKs in FastLine.
We do not use the advertising identifier (IDFA), so the App Tracking Transparency prompt does not apply, and we do not track you across other companies' apps or websites.
We do not sell your data, and we do not share it with data brokers.
We do not ask for your name, email address or contact information.

5. Data retention

Content you create stays on your device until you delete it or remove the app. Anonymous analytics and crash data are retained by Google for up to 14 months. The device record held by our notification service is kept while you use the app; deleting the app stops it being updated.

6. Your choices

You can turn notifications off at any time in iOS Settings, which stops announcements. Deleting the app removes the content stored on your device. If you would like us to delete the device record associated with your install, email us and we will do it.

7. Children

FastLine is not directed at children under 13, and we do not knowingly collect personal data from children. The app has no social features, no chat, and no user-generated content shared with others.

8. Changes to this policy

If this policy changes, we will update this page and the “last updated” date above.

9. Contact

Questions? Email kenz@kenzapps.com.