Effective date: October 23, 2026 · Last updated: October 23, 2026

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We do not use your personal data to train large language models.

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Who we are: GymKin, Inc., a Colorado corporation, the developer of the GymKin app and the GymKin motion sensor. Contact: support@gymkin.com.

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GymKin is a workout tracker that pairs with a small Bluetooth motion sensor you attach to gym equipment. The sensor streams motion data to your phone, where the app counts your reps and computes technique stats. This policy explains what data the app handles, where it lives, and what leaves your phone.

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The short version

• Set videos you record stay on your device; they are never uploaded.

• Your raw sensor recordings stay on your device unless you choose to contribute them (Profile → Contribute your sets, off by default). If you do, each set's recording is uploaded so we can improve rep detection; you can stop at any time, and deleting your account deletes them.

• Your account (email) and your workout history (exercises, sets, reps, weights, stats) are stored in our cloud database so your history survives reinstalls and signs in across devices.

• We use crash reporting (Sentry) to fix bugs. We do not use advertising networks, we do not track you across other apps or websites, and we do not sell your data.

• You can delete your account and its data from inside the app at any time.

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Data we collect and why

Account information

When you create an account (email/password, Sign in with Google, or Sign in with Apple) we store your email address and account-creation date, and Firebase Authentication (Google) manages your sign-in credentials. If you use Sign in with Apple you may hide your email; we then receive Apple's private relay address instead. We use this only to operate your account.

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Profile information (optional)

If you fill out your profile: display name, username, bio, fitness goals, and a profile visibility setting. A profile photo can be selected from your photo library, but photo upload is switched off in this version of the app: the photo you pick is not sent anywhere.

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Workout and fitness data

What you log and what the sensor pipeline computes: exercises, equipment, set and rep counts, weights, timestamps, and derived per-rep/per-set technique stats (rep pace, range of motion, time under tension, estimated power, control score, estimated one-rep max, confidence scores). For sets recorded with the sensor it also includes the sensor's name (which contains part of its hardware address), its Bluetooth identifier, the sensor's capture counters, and any capture note you typed (Labs → Capture notes). This is stored under your account in our cloud database (Google Cloud Firestore) so your history is durable — for every user, whether or not you contribute recordings. It is fitness data linked to your account; we use it only to show you your own history and progress.

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Raw motion-sensor data — on your device, unless you contribute it

While recording a set, the GymKin sensor streams accelerometer and gyroscope readings over Bluetooth to your phone, where reps are detected on-device. A compact raw recording of each sensor set is archived on your phone (capped storage, oldest sets evicted automatically). You can export a recording yourself (for example, to attach to a support request about a miscounted set); an export contains motion data and set metadata (exercise name, equipment, rep counts) but no name or email.

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Contributing your sensor recordings (optional, off by default)

If you turn on Contribute your sets (Profile), the app uploads each set's recording to our cloud storage (Google Cloud Storage, via Firebase) so we can review it and improve GymKin's rep detection, including training the models that count reps. What a contributed recording contains:

• the raw accelerometer and gyroscope samples, with their timestamps;

• the exercise, equipment, mount and weight you logged;

• the rep count the app recorded, the count you confirmed or corrected (if you did), the per-rep technique stats, and any crop you applied;

• the sensor's name (which contains part of its hardware address) and its Bluetooth identifier (on iPhone, an ID iOS assigns to the sensor), and the sensor's own capture counters;

• the date and time of the set, the IDs that link it to your workout history, the set's overall stats, and the app's internal confidence scores and alternative-algorithm counts;

• a pseudonymous contributor ID derived from your account (not your name or email). The upload is stored under your account ID so it can be deleted with it — it is linked to your account, not anonymous;

• any capture note you typed for the set (Labs → Capture notes), and app diagnostic notes (for example, that a set was recovered after the app closed mid-set).

How it works: uploads start only when your phone is on Wi-Fi and run while the app is running. When you turn it on you choose whether sets already saved on your phone are included (unticked by default); otherwise only sets recorded after you agree are uploaded. The app records, on your phone, when you agreed and which version of this text you agreed to, and tags each upload with that version; if we change what we collect, uploads stop until you agree to the new version in Profile → Contribute your sets.

Turning it off stops uploads (one already in progress may finish), and you can choose to delete the sets you've already sent at the same time, or later from the same screen. Deleted sets can't be restored.

How long we keep them: we keep contributed recordings until you delete your account or ask us to delete them (support@gymkin.com). Once a year we delete any we no longer need to build and test rep counting. Deleting your account deletes the recordings you contributed from our cloud storage first; if that step fails, the app stops before deleting anything else and asks you to try again. Labels and summary records we derived from your recordings are deleted within 30 days of your account deletion or deletion request. Counting software we have already built or tuned with your recordings stays in use; it does not contain the recordings themselves. We do not sell contributed recordings, use them for advertising, or share them with third parties to train their own AI models. We treat contributed recordings as consumer health data under Washington's and Nevada's laws; our Consumer Health Data Privacy Policy, at www.gymkin.com/consumer-health-data, explains what that means and how to use your rights. To contribute you must confirm that you are 18 or older.

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Set videos — stay on your device

Video mode lets you film a set (with audio) to review your form. Recordings are stored only on your phone and are never uploaded. Deleting the app deletes them.

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Crash and diagnostics data

We use Sentry for crash reporting. When the app crashes or hits an error, we receive: the error and stack trace, device model, OS version, app version, session health signals (e.g. whether sessions end in a crash), and a breadcrumb trail of recent in-app events (screen and action names, with rep counts removed — never your email or raw sensor samples). Crash reports are not used for advertising, and Sentry keeps them for up to 90 days.

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What we do NOT collect

• No location data on iOS. (On Android, the system requires the location permission for legacy Bluetooth scanning; we request it there solely to find your sensor and never record a location.)

• No contacts, no health records, no Apple Health / HealthKit access.

• No advertising identifiers, no cross-app tracking, no analytics SDKs beyond the crash reporter described above.

• We do not sell or rent personal data. We have never done so.

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Where data is processed

Cloud data is stored with Google Firebase (Authentication, Cloud Firestore, and — for contributed sensor recordings — Cloud Storage) and crash data with Sentry (Functional Software, Inc.). We use Anthropic's Claude to help analyse contributed recordings, with model training on our data switched off. These providers process data on our behalf under their own security and data-processing terms.

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Data retention

• Account and workout data: kept until you delete your account.

• Contributed sensor recordings: kept until you delete your account or ask us to delete them, and reviewed once a year to delete any we no longer need to build and test rep counting. Turning contribution off stops new uploads but does not delete what was already uploaded (ask us to, or delete your account). Labels and summary records derived from them are deleted within 30 days of an account deletion or deletion request.

• On-device data: the raw sensor archive is kept on your phone under a storage cap and deleted when you sign out, delete your account, or delete the app. Set videos stay in the app's storage until you delete the app.

• Crash data: kept by Sentry for up to 90 days, then deleted.

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Deleting your account

Profile → Privacy & account → Delete account…. This permanently deletes your auth account and purges your cloud data: workout history, account doc, profile, calibration data, posts, goals, custom exercises, friend requests, and the sensor recordings you contributed. Saved training programs are not yet removed by the in-app deletion; email support@gymkin.com and we will delete them. If you signed in with Apple, we also revoke the Apple sign-in token. Deleting requires a recent sign-in: if yours isn't, the app asks you to sign in again before anything is deleted. Your contributed recordings are deleted first; if that fails, the app stops before deleting anything else and asks you to try again. If another part of the cleanup fails, the app tells you; email support@gymkin.com and we will finish it. Notifications previously delivered to other users (e.g. a friend-request message containing your username) and crash reports already collected may persist until their normal retention expires.

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Children

GymKin is not directed at children under 13 (or the equivalent minimum age in your jurisdiction), and we do not knowingly collect data from them.

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Your rights

GymKin is offered in the United States. Depending on where you live (for example, California's CCPA), you may have rights to access, correct, export, or delete your personal data. The in-app deletion flow covers deletion; for anything else, email support@gymkin.com and we will respond within 30 days.

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Changes to this policy

We will post changes here and update the effective date. Material changes will be announced in the app.

Contact: support@gymkin.com