StackFlow
Last updated: April 8, 2026

Privacy Policy

This policy applies to the StackFlow app, website, support pages, and related services operated by Hangdong Guo.

Operator and scope

StackFlow is operated by Hangdong Guo, an independent developer. This policy applies to the StackFlow iOS app, website, support pages, and related account, subscription, and AI features.

Information we collect

01
Account and sign-in data Email address, Sign in with Apple identifiers, authentication state, and information needed to maintain signed-in access.
02
Profile and routine data Profile details, goals, supplement stacks, check-ins, notes, feeling logs, and inputs used when AI features are requested.
03
Subscription and transaction data Subscription product, entitlement, renewal, and restore status made available through Apple StoreKit and the App Store.
04
Support and technical data Support requests, timestamps, app or device version details when available, and limited service logs created to operate and secure the service.

How the data is used

01
Run accounts and sync Authenticate the user, maintain session continuity, and show routine, history, and membership access correctly.
02
Deliver AI features When the user asks for AI planning, explanations, or insights, process the relevant profile and routine context to generate those outputs.
03
Security and support Diagnose reliability issues, prevent abuse, answer support requests, and protect the service.
04
Legal and compliance needs Retain or disclose limited records when required for tax, audit, fraud prevention, or other legal obligations.

Sharing and service providers

StackFlow does not sell personal data. We may share data with the following service providers only as needed to operate the service:

01
Supabase Authentication, account sessions, and cloud-hosted user data.
02
Google Gemini AI planning, explanation, and insight generation when the user actively invokes those features.
03
Railway, Vercel, and Cloudflare Application hosting, website delivery, DNS or CDN, network protection, and object storage when enabled.
04
Apple App Store subscriptions, renewal handling, restore purchases, and entitlement processing through StoreKit.

International processing and retention

Data may be processed in countries other than the user’s own. Account, routine, and subscription data are generally kept while the account remains active. Logs, backups, and security records may be kept for shorter or longer periods when operationally necessary or legally required.

Deletion, export, and user rights

Users can request account deletion in the app under Settings > About & Help > Delete Account or by emailing privacy@stackflow.life. We aim to complete deletion of account data within 30 days after a valid request, although limited backup, security, fraud prevention, or legal records may be retained for longer where necessary. Where applicable, including in the EEA, UK, Switzerland, and certain U.S. states, users may also request access, correction, export, deletion, or restriction of their data as required by law. App Store subscription management and refunds are handled by Apple.

Children and health boundary

StackFlow is a consumer app for supplement routine planning and is not intended for children under 13 or the minimum digital consent age in the user’s region. StackFlow does not provide medical advice, diagnosis, or treatment.