Effective date: September 28, 2026 | Last updated: September 28, 2026
This policy explains what information Stackd collects, how we use it, who we share it with, and the choices you have. We wrote it to be read, not skimmed past. If anything is unclear, email support@stackd.health.
Stackd is a mobile app and website (stackd.health) operated by Gabriel Mzaouakk as a sole proprietorship based in Massachusetts, United States ("Stackd", "we", "us"). We are responsible for your personal information as described in this policy.
Contact: support@stackd.health
This policy covers the Stackd iOS app, the stackd.health website, and any support conversations you have with us.
If you turn on Apple Health access, Stackd can read the data types you approve, which may include steps, heart rate, resting heart rate, heart rate variability, blood oxygen, respiratory rate, sleep, active energy, and body weight. Stackd does not read your workouts from Apple Health. Stackd can write workouts you complete in Stackd to Apple Health if you turn that on when saving a workout. You can change or revoke this at any time in the iOS Settings app under Health, Data Access and Devices.
Stackd does not include advertising SDKs, third-party analytics SDKs, or crash-reporting SDKs, and we do not track you across other companies' apps or websites.
Subscriptions are sold and billed by Apple. We receive your subscription status (for example, active, trial, or expired) through Apple and our subscription provider RevenueCat. We never receive your payment card details.
We do not sell your personal information. We do not use your health information for advertising, and we do not share it with advertisers or data brokers.
Stackd's AI features are powered by Claude, a model provided by Anthropic, PBC. AI features only run after you give consent in the app, and you can withdraw that consent at any time in Settings. If you withdraw consent, AI features stop working, and the rest of the app keeps working.
What we send to Anthropic when you use an AI feature, limited to what that feature needs:
Apple Health data. Stackd does not send Apple Health data to Anthropic as it reads it. The one exception is body weight: if you allow weight access, weights Stackd imports from Apple Health are saved to your weight log and profile, and like a weight you enter yourself, your current weight can be included with your health profile in AI requests and your weight trend in monthly reports. Steps, heart rate, resting heart rate, heart rate variability, blood oxygen, respiratory rate, sleep, and active energy from Apple Health are never sent to Anthropic.
What we never send: your name, email address, password, or payment information.
Under Anthropic's commercial terms, information sent through its API is not used to train its models. Anthropic may keep API data for a limited time for safety and abuse monitoring, as described in its own policies.
AI output can be wrong. See our Medical Disclaimer.
To look up nutrition facts, exercise information, and published research, Stackd queries public databases such as USDA FoodData Central and PubMed. These lookups contain search terms only, such as a food name or a biomarker, and never your identity.
We share information only with service providers who help us run Stackd, and only as needed for them to do that job:
| Provider | Purpose |
|---|---|
| Supabase | Database, authentication, file storage, and server functions (United States) |
| Anthropic | AI features, as described in Section 5 |
| Apple | App distribution, Sign in with Apple, subscriptions, Apple Health, and push notifications |
| RevenueCat | Subscription status and entitlement management |
| Expo | App updates and push notification delivery |
| Optional Google sign-in |
Sharing to Instagram, Messages, and other apps. When you tap a share button, the image you created is handed to the app you choose, such as Instagram, through iOS. Stackd uses a Meta App ID only so Instagram can open its Stories editor. Stackd does not send your account, health data, or any other information to Meta. Photos you pick as a share background stay on your device and are never uploaded to us.
We may also disclose information if required by law, to protect the safety of any person, or as part of a business transfer, in which case this policy will continue to apply to your information.
Your data is stored with Supabase in the United States. We protect it with encryption in transit (HTTPS), hashed passwords, access controls that isolate each account's data (row-level security), and private storage for uploaded files. No system is perfectly secure, but we work to protect your information and will notify you of a breach as required by law.
Stackd is not a healthcare provider and is not covered by HIPAA. Please do not use Stackd to store records you need HIPAA protection for.
Wherever you live, you can:
We respond within 30 days and will not treat you differently for using your rights.
California, other US states, and Washington. Depending on where you live, you may have rights to know, access, correct, delete, and port your personal information, to limit the use of sensitive information, and to opt out of sale, targeted advertising, or profiling. We do not sell personal information or use it for targeted advertising or profiling. Health information you give Stackd is used only to provide the features you request, and is never shared except as described in Section 7. To use any of these rights, email support@stackd.health. You may use an authorized agent, and you may appeal our decision by replying to our response.
European Economic Area, United Kingdom, and Switzerland. If these laws apply to you, we process your information to provide the service you signed up for (contract), with your explicit consent for health data and AI features, and for our legitimate interest in keeping Stackd secure. You have rights to access, correct, delete, restrict, object, and port your data, and to withdraw consent at any time. You may also complain to your local data protection authority. Your data is processed in the United States.
Stackd is for adults 18 and over. We do not knowingly collect information from anyone under 18. If you believe a minor has created an account, email us and we will delete it.
If we make material changes, we will notify you by email or in the app at least 14 days before they take effect. The date at the top shows when this policy last changed.