Privacy Policy — Fasting Well

Last updated: May 24, 2026

Fasting Well (“the app,” “we”) is built by Generalize LLC (“we,” “us”). This policy describes exactly what data the app collects, what it does with it, and what it does not.

It is written in plain English. If anything here is unclear, email us at hello@fastingwell.app and we’ll fix it.

The short version

• Your fasting, weight, mood, and journal data stays on your device. We do not have a server. We do not have your account. We could not look up your data even if we wanted to.
• We collect anonymous usage signals through PostHog so we can know which features get used. These signals contain no personally identifying information and no fast / weight / mood values. You can turn them off at any time in Settings → Privacy → Share anonymous usage data.
• Optional sync with Apple Health / Health Connect is off by default. If you turn it on, the app reads your latest weight from the system store and (on iOS) writes completed fasts as mindful sessions. You can revoke permission at any time in your device’s Health settings.
• We never sell data, never show ads, never require an account.

What data the app stores on your device

All of this lives in your phone’s local AsyncStorage and never leaves the device unless you choose to share it:

• Completed fasts (start time, end time, goal length, plan, optional mood/energy/notes/what-broke-the-fast)
• Active fast in progress (if any)
• Weight entries (kg)
• Profile (the optional reason / experience-level / preset you picked during onboarding)
• Custom protocols
• App settings (theme, units, notification preferences, etc.)
• First install timestamp (used to grant lifetime Pro for free to early-adopter users when Pro launches in a future version)

You can wipe all of this in one tap via Settings → Data → Reset everything.

What we send off the device

Anonymous usage analytics (PostHog)

To know what to improve, the app sends a small set of anonymous events to PostHog (a privacy-respectful analytics service, GDPR-compliant). These events describe what action happened — never what value. Examples of what we send:

• fast_started with the plan you chose (e.g. lean-16-8)
• fast_completed with whether you hit your goal (true/false)
• stage_crossed with the stage IDs (e.g. catabolic → fatBurning)
• weight_logged with whether you have prior history (true/false)
• article_opened with the article ID and category
• Lifecycle events PostHog captures by default: $app_opened, $app_backgrounded, $app_installed, $app_updated

We never send: your weight value, your fast duration, your mood, your energy, your notes, your custom protocol details, your name, your email, your IP address (PostHog strips IPs by default in our configuration), or any identifier that could be tied back to you.

PostHog issues a random anonymous ID per install that we use to count unique users — but that ID is not linked to any personal information.

To opt out: Settings → Privacy → toggle off Share anonymous usage data. The opt-out takes effect immediately.

Crash and error reports (PostHog Error Tracking)

If the app crashes or throws an unhandled error, we send the error message and a stack trace to PostHog so we can fix it. These reports include code locations but not your fasting/weight/mood data.

This is part of the same analytics opt-out — if you turn off analytics, error reports stop too.

Apple Health / Health Connect (only if you opt in)

If you enable Settings → Health → Sync with Apple Health (or Health Connect on Android):

• We read your most recent weight entry from the system health store and offer to import it when you tap “Log weight.”
• On iOS, when you complete a fast, we write it to Apple Health as a mindful session so it shows up alongside your other wellness data.
• On Android, we currently only read weight — Health Connect doesn’t have a record type for fasting yet, so we don’t write anything back.

This data flows between your app and the system’s local health database. It does not pass through any server we operate. You can revoke this permission any time in your phone’s Settings → Privacy & Security → Apple Health (iOS) or Health Connect (Android).

Local notifications

Stage-transition, goal-reached, and eating-window reminders are scheduled with the operating system on your device. They do not round-trip through any server. We do not use push notifications.

Share-card image (only when you tap Share)

When you tap “Share image” on a completed fast, the image is composed entirely on your device. It is only sent anywhere if you explicitly pick an app from the system share sheet. Fasting Well never uploads the image automatically.

Article content (Learn tab)

The Learn articles ship inside the app bundle. Opening an article does not make a network request to us. (Anonymous “article opened” analytics events are sent only if analytics is enabled.)

What we don’t do

• We don’t have user accounts or sign-in.
• We don’t sell, rent, or share your data with third parties.
• We don’t show ads or sponsored content.
• We don’t train AI models on your fasting or weight history.
• We don’t track you across other apps or websites (no advertising identifiers, no fingerprinting).

In-App Purchases (Pro tier — coming in a future version)

The current version of Fasting Well (v1.0) is free. A future version will add a Pro tier with custom protocols, unlimited history, weight tracking, share cards, and other features.

When Pro launches:

• Purchases will be processed by Apple App Store (iOS) or Google Play Store (Android). We never see your payment information.
• Subscription state will be managed by RevenueCat, a subscription infrastructure provider. RevenueCat receives an anonymous App Store / Play Store user ID and our app’s product IDs. It does not receive your name, email, or payment information.
• Users who installed the app before Pro launched will be automatically granted lifetime Pro for free as an early-supporter (“founder”) benefit. We use your install date (stored on-device) to determine eligibility.

This policy will be updated when Pro ships to fully reflect what RevenueCat receives.

Children’s privacy

Fasting Well is not directed at children under 13. We do not knowingly collect data from children. If you believe a child has used the app, contact us at hello@fastingwell.app and we’ll help.

For users under 18, please consult a doctor before practicing extended fasting.

Your rights (GDPR / CCPA / state privacy laws)

Because we do not have your personal data on any server, there is nothing for us to access, correct, port, or delete on your behalf. All of your data lives on your device under your control.

If you want to:

• Access your data: tap any screen — it’s all in the app.
• Export your data: Settings → Data → Export fasts (CSV) / Export weights (CSV).
• Delete your data: Settings → Data → Reset everything (one tap, instant, on-device).
• Stop analytics: Settings → Privacy → toggle off Share anonymous usage data.

If you’ve already disabled analytics and want to ask PostHog to delete the anonymous event records that were sent before, email us at hello@fastingwell.app with the request and the approximate dates and we’ll initiate a PostHog deletion on your behalf.

Changes to this policy

If we change anything material in this policy, we will:

1. Update the “Last updated” date at the top.
2. Note the change in the app’s “What’s New” release notes for the next version.

If the change affects what data we collect, we will surface a one-time in-app notice before any change takes effect.

Contact

• Email: hello@fastingwell.app
• Operator: Generalize LLC, USA