Strength Trainer

Strength Trainer is a hypertrophy training app operated by Hydra Labs LLC (“we”, “us”). This policy explains what data we collect, why, and your choices. We do not sell your data, and we do not track you across other apps or websites.

Information we collect

Account information — when you create an account we collect your name, email address, and a securely hashed password. This is used to authenticate you and associate your training data with your account. If you ask to reset your password, we email you a 6-digit code; we store only a hash of the code, and it expires after 15 minutes.

Sign in with Apple (optional) — if you continue with Apple, we receive from Apple an identifier for your Apple Account that is unique to our app, the email address you chose to share (which may be a private relay address from Hide My Email; emails we send it are forwarded to you), and, the first time only, your name. We also store a token from Apple, used only to disconnect Sign in with Apple from the app when you delete your account. We never see or ask for your Apple Account password. You can stop using your Apple Account with the app at any time in iOS Settings → [your name] → Sign in with Apple.

Training data — the workouts, sets, weights, reps, exercise preferences, recovery/volume metrics, gym equipment, and settings you create in the app. This is used solely to provide the app’s core functionality (generating and tracking your training).

Cardio sessions — when you finish a cardio session we store its type, the activity (for example running or cycling), start and finish times, active duration, any target duration you set, and for HIIT sessions the planned and completed rounds and the work and rest interval lengths. If a session cannot be saved straight away, it is kept on your device until our server confirms it. Cardio sessions are used to show your cardio history and weekly totals.

Apple Health (optional) — if you grant permission, the app writes your completed strength workouts and cardio sessions (workout type, start time, and end time) to Apple Health. The app does not read your Health data. You can revoke this at any time in iOS Settings → Health → Data Access & Devices. Health data is stored by Apple on your device and is not transmitted to our servers.

Subscription (Strength Trainer Pro) — Strength Trainer Pro is an auto-renewable subscription sold and processed by Apple through the App Store. Apple handles payment; we never receive your card or other payment details. When you subscribe, restore or open the app, the app sends the App Store’s signed record of your subscription to our server, and Apple notifies our server when it renews, fails to renew, expires or is refunded. We store, linked to your account: the subscription’s App Store transaction identifier, the product, whether it is a free trial, active, in a billing grace period, expired or refunded, its expiry and renewal dates, whether it will renew, and whether it was bought in Apple’s test environment. We use this only to decide whether your account can use Strength Trainer Pro features. We give Apple your account ID (a random identifier) so the purchase is linked to your account. Apple’s handling of your purchase is covered by Apple’s own privacy policy.

Feedback (optional) — if you send feedback from the app, we collect your message and the feedback type (bug, idea, or other). The app automatically attaches your app version and build number, iOS version, iPhone model, the screen you sent it from, and whether a workout was in progress. Feedback is linked to your account. If you allow it (“You can email me about this”), we also include your email address so we can reply. Feedback is used only to fix problems and improve the app.

How we use your information

To authenticate you and keep you signed in.
To generate workouts and track your progress, recovery, volume, and cardio.
To read and act on feedback you send, and to reply if you allowed it.
To operate, maintain, and improve the app’s functionality.

We use your data only for app functionality. We do not use it for advertising, and we do not use tracking as defined by Apple’s App Tracking Transparency framework.

Data storage and security

Account and training data are stored in our hosted database (Supabase/Postgres) and served via our backend on Vercel. Connections use HTTPS. Passwords are stored only as salted hashes; we never store plaintext passwords.

Data sharing

We do not sell or rent your personal data. We share data only with the service providers below, and only as needed to run the app:

Supabase (database) and Vercel (hosting) store and serve your account and training data.
Linear, the issue tracker we use to plan work, receives the feedback you send and processes it on our behalf. Each feedback ticket contains your message, the details attached automatically (listed above), and your account ID. Your email address is included only if you choose to let us contact you.
Resend, our email delivery provider, receives your email address and the reset code to send password-reset emails. It is used only when you ask to reset your password.
Apple processes subscription purchases, tells our server about changes to your subscription, and stores any workouts you allow the app to write to Apple Health.
Apple provides Sign in with Apple, if you choose to use it, and forwards the emails we send to private relay addresses.
RepDB (exercise-dataset.com) hosts most of the exercise demonstration images. Your device downloads these images directly from RepDB, and the rest from our own site, so those hosts receive your device’s IP address and standard request information (such as the time of the request and the image requested), as with any website. No account or training data is sent to RepDB.

Account deletion

You can permanently delete your account and all associated data at any time: Profile → Delete Account. This immediately and irreversibly removes your account, workouts, sets, cardio sessions, settings, gym profiles, feedback, subscription records, and training history from our database. As part of deletion, we also remove your email address from any feedback tickets in Linear; the feedback message and attached app details remain there without your contact details.

If you use Sign in with Apple, deletion also revokes the app’s Sign in with Apple tokens with Apple, which disconnects your Apple Account from Strength Trainer, before your data is deleted.

Deleting your Strength Trainer account does not cancel your Strength Trainer Pro subscription. Apple manages the subscription, so to stop being charged, cancel it in iOS Settings → [your name] → Subscriptions (or in the app under Profile → Subscription → Manage Subscription, which opens Apple’s subscription settings).

Children

The app is not directed to children under 13, and we do not knowingly collect data from them.

Changes to this policy

We may update this policy from time to time. Material changes will be reflected by the “Last updated” date above.

Contact

For privacy questions or requests, contact: privacy@strengthtrainer.app

For help using the app, see our Support page.