Heracles · Quatron Studios · Last updated 24 September 2026
Heracles is a personal training app. It stores your workouts, body measurements, meals and progress photos so an AI coach can build and adjust a training program for you. This policy explains exactly what it collects, where that data lives, and how to get rid of it.
Heracles is published by Quatron Studios, the data controller for the information described here. Contact: support@quatronstudios.com.
| Data | Why | Linked to you |
|---|---|---|
| Name, email address, profile picture | Your account identity, from Sign in with Apple or Google | Yes |
| Body photos (three guided angles) | AI analysis of your physique against your chosen goal, and progress comparison over time | Yes |
| Body measurements: weight, body fat, girths | Progress tracking and program adjustment | Yes |
| Training sessions: exercises, sets, weights, duration | The training log the whole app runs on | Yes |
| Daily check-ins: calories, protein, steps, habits | Adherence tracking and coaching | Yes |
| Meal photos and nutrition estimates | AI calorie and macro estimation | Yes |
| Step count from Apple Health | Pre-fills your daily check-in | Yes |
| Device name and sign-in timestamps | So you can see and revoke the devices signed into your account | Yes |
Heracles reads your step count only, and only after you grant permission in the Health app. It never writes anything to Health. Health data is used solely to fill in your daily check-in. In line with Apple’s rules, Health data is never used for advertising or marketing, and is never sold or shared with data brokers.
Your data is stored on servers operated by Quatron Studios, in a PostgreSQL database, with photos held as files on the same server. Access to the app’s API requires a per-device token issued when you sign in, transmitted over HTTPS. Tokens are stored on your iPhone in the system Keychain, and only a hash of each token is kept on the server.
To generate your program, analyse your photos, estimate meal nutrition and write coaching messages, Heracles sends the relevant data to an AI provider, which processes it and returns a response. That data can include your body photos, meal photos, measurements and training history. Which provider depends on the task:
| What | Provider | What it receives |
|---|---|---|
| Writing and revising your program; the season checkpoint | Anthropic (Claude API) | your physique photos, measurements, training history and the facts you entered |
| Coach chat; meal photo analysis; the daily nudge and weekly digest | DeepSeek | your meal photos and the training context relevant to the message |
Heracles does not use your data to train any AI model, and does not permit its processors to do so. Both providers process data outside your country; we rely on their contractual terms for that transfer.
Apple and Google receive only what is inherent in signing in with their identity services, and see nothing about your training, photos or health.
Subscriptions are sold as in-app purchases and charged by Apple. Apple handles the payment; your card number, billing address and receipts never pass through Heracles and we could not see them if we wanted to.
We use RevenueCat to tell us whether a subscription is active. It receives your Heracles account id and the purchase details Apple gives it, and it tells our server when a subscription starts, renews, lapses or is refunded. What we store from that is small and deliberate: which entitlement you hold, whether it is active, when it expires, which product it came from, and whether it will renew. RevenueCat receives nothing about your training, your photos or your health.
You manage and cancel a subscription in your Apple account, not here. See the Terms of Use.
Where the GDPR applies, the legal basis for processing is the performance of a contract with you (running the app you asked for) and, for health data specifically, your explicit consent, given when you grant photo, camera and Health permissions. You may withdraw consent at any time by revoking those permissions in iOS Settings or by deleting your account.
Data is kept until you delete it. Deleting your account removes it immediately, as described below. Ordinary server backups may retain a copy for up to 30 days before being overwritten.
Deleting your account does not cancel a subscription: Apple holds that, and you cancel it in your Apple account.
Open Progress → Profile → Delete account. This permanently erases your account and everything attached to it: every training session, check-in, measurement, meal, generated program and coaching message, all of your photos as files on disk, and every device token. It happens immediately and cannot be undone. If you would rather have it done for you, email support@quatronstudios.com from the address on your account.
Depending on where you live, you may have the right to access, correct, export or erase your data, to object to or restrict processing, and to complain to a data protection authority. The app itself covers access (everything is visible in the app) and erasure (the delete button). For anything else, email support@quatronstudios.com; we respond within 30 days.
Heracles is not directed at children and is not intended for anyone under 16. The app refuses a date of birth younger than that. We do not knowingly collect data from children. If you believe a child has created an account, contact us through the support page and we will delete it.
Heracles produces training and nutrition suggestions generated by an AI system. It is not a medical device and does not provide medical advice, diagnosis or treatment. Consult a qualified professional before starting any exercise or nutrition program, particularly if you have an injury or a medical condition.
If this policy changes materially, the app will show the update before you continue using it, and the date at the top of this page will change.