Fastory is an intermittent-fasting tracker that takes your privacy seriously. This policy explains what we collect, why, and what you can do about it. If anything here is unclear, email us.
Who we are
Fastory is built by HealthyAI Studio, an independent developer based in Chanthaburi, Thailand. We are the data controller for the information described below.
Account info — email address (if you sign up with email), Apple ID identifier (if you use Sign in with Apple), Google account identifier (if you use Sign in with Google).
Display name — the name shown on the leaderboard. You set this yourself; it can be anything within 2–24 characters.
Profile data — your fasting protocol preference, height, goal weight, unit preferences (kg/lb, cm/in), date format, time format.
Fast logs — start time, end time, protocol, notes you add.
Health logs — weight, water intake, hunger level, body measurements (waist, chest, hips, thigh) — only if you log them.
Journal entries — mood, body symptoms, meals, free-text notes, and optional photos you attach.
Information we collect automatically
A randomly generated user ID (Firebase Auth, anonymous by default until you sign up).
Device timezone (so timers show correct times).
Crash reports — only if a crash happens, and only the technical stack trace.
Information we do NOT collect
Your real name (unless you put it in your display name).
Your location.
Your contacts.
Browsing history outside the app.
Advertising identifiers (IDFA / GAID). We do not advertise.
How we use your information
Run the core app — track fasts, show history, compute streaks and achievements.
Generate AI Coach insights after each fast. Free users get template-based insights generated locally on our server (no data leaves Firebase). Premium users have their fast duration, protocol, recent history, and (if logged) journal/water context sent to OpenAI's GPT-5-mini for a personalized written insight.
Show the leaderboard — your display name and total points are visible to all signed-in users.
Send notifications you opt into (stage transitions, goal reached, daily reminders). You can turn these off in Settings.
Debug and improve the app.
Who we share data with
We share your data only with the processors below, contractually bound to use it solely to provide their service to us. We do not sell your data, share it for advertising, or use it for purposes outside this app.
Firebase (Google LLC) — authentication, database (Firestore), file storage, server functions. Hosted in Singapore (asia-southeast1).
OpenAI, L.L.C. — receives fast data (numeric duration, protocol code, and recent fasting history) to generate AI Coach insights for premium subscribers. No identifying information (name, email, uid) is sent. Free users' data is never sent to OpenAI.
Apple Inc. — if you use Sign in with Apple.
Google LLC — if you use Sign in with Google, in addition to providing Firebase services.
RevenueCat, Inc. — when subscriptions launch, manages subscription state across devices.
Data retention
Active accounts — kept as long as your account exists.
Deleted accounts — when you choose Delete Account in Settings, all your data (auth record, fast sessions, journals, health logs, insights, leaderboard profile, photos) is permanently removed within 30 days.
Anonymous (not-signed-up) users — data is tied to the install. Uninstalling clears the local identifier; the cloud copies become orphaned (accessible only by Firebase service accounts, never by us) and are purged in batches.
Your rights
You can at any time:
Access your data — view everything you've logged within the app.
Edit any entry — fast sessions, journals, weight, etc.
Export your data — email us and we'll send a JSON export within 30 days.
Delete your account — Settings → Me → Delete account. This wipes everything. It cannot be undone.
Withdraw consent — uninstall the app and request deletion via email.
EU/UK residents have additional rights under GDPR (right to lodge a complaint with your supervisory authority). California residents have rights under CCPA. To exercise these, email arachimay@gmail.com.
Children
Fastory requires users to be 16 or older. Intermittent fasting can be unsafe for adolescents and may interfere with normal growth. We do not knowingly collect data from anyone under 16. If we discover we have, we delete it.
Security
All data is encrypted in transit (TLS 1.2 or higher) and at rest (Google Cloud default encryption).
Authentication credentials are handled by Firebase Auth using industry-standard hashing — we never see or store your password.
Our Cloud Functions run in a private Google environment.
Cookies and tracking
Fastory is a native mobile app. It does not use browser cookies. We do not use cross-app analytics, fingerprinting, or advertising identifiers.
International transfers
Your data is stored on Google Cloud servers in Singapore. If you're in the EU/UK, your data leaves the EEA. We rely on Google's standard contractual clauses to safeguard this transfer.
Changes to this policy
We'll notify you in-app if we make material changes. The "Last updated" date above will reflect the change. Continued use of the app after the change indicates you accept the new policy.