Billet Privacy Policy

Billet is a strength-training app made by an individual developer. This policy is short because the honest answer is short: your data stays on your phone.

What Billet collects

Billet stores, on your device only:

• Workout data — programs, logged sets (weight, reps, distance, time), RPE, notes, personal records, and workout session times.
• Heart-rate data — live readings from a Bluetooth heart-rate sensor you choose to connect, stored as a stream and as per-set summaries. Raw stream samples are kept for 90 days; per-set summaries are kept with your workout history.
• Optional calorie profile — body weight, age, and a formula choice you may enter to enable calorie estimates.
• Step counts — read from your phone's health store, if you grant permission.
• Apple Health data — iPhone/Apple Watch (only if you grant permission) — heart rate, heart-rate variability, sleep, steps, and workout data that Billet reads from HealthKit, and workouts Billet writes back to HealthKit at your request. If you use the Apple Watch app, the watch measures your heart rate during a workout and sends it to your iPhone; it is stored the same way as any other heart-rate reading.
• Health Connect data — Android (only if you grant permission) — Billet reads heart rate, resting heart rate, heart-rate variability, sleep sessions, and steps from Health Connect. Billet only READS from Health Connect; it does not write to it.

Billet requests each of these permissions so it can show your training and recovery data alongside your workouts inside the app, and for no other purpose. Health and fitness data obtained through Apple HealthKit or Android Health Connect is never transmitted off your device, never used for advertising or marketing, and never sold or shared with third parties.

Payments and subscriptions

Billet offers a paid subscription.

• Billing is handled entirely by Apple or Google. Purchases go through the App Store (Apple) or Google Play (Google) using the payment method already on your store account. Billet never sees, receives, or stores your card details, billing address, or any payment information.
• What the developer receives is what every app developer receives from the stores: aggregate, anonymised sales and payout reports. These do not identify you.
• No account is required to subscribe. Your subscription is tied to the App Store or Google Play account you bought it with, not to a Billet login — there is no Billet login. "Restore Purchases" re-checks entitlement with the store on a new install or a new device.
• Subscriptions are per platform. A subscription bought on iOS is recognised by iOS, and one bought on Google Play is recognised on Android, because entitlement is verified on-device against the store you bought from. Billet keeps no server, so there is nothing holding a cross-platform account.
• Managing or cancelling is done in the store, not in Billet: iOS Settings → Apple Account → Subscriptions, or Google Play → Payments & subscriptions. Refunds are handled by Apple and Google under their policies.
• Subscription status does not affect any of the above. Paying does not send your training or health data anywhere; not paying does not delete it.

Apple's and Google's own privacy policies cover how they process your payment. They are the data controllers for that transaction, not Billet.

What Billet does NOT do

• No accounts. There is nothing to sign up for.
• No servers. Billet has no backend; your data is never uploaded, synced, or transmitted to the developer or anyone else. This is true of paid and unpaid use alike — see Payments above.
• No analytics, no tracking, no ads. Billet contains no third-party analytics or advertising SDKs.
• No sale or sharing of data. Nothing leaves your device unless you explicitly export it.
• Health data is never used for advertising or marketing, and never will be — this is also an Apple requirement Billet embraces.

Your controls

• Export — you can export your complete data as a backup file, and share programs as .billet files, at any time. Files you share go where YOU send them; that sharing is under your control.
• Delete — deleting the app deletes everything Billet stored on your device. Two things deliberately survive, because they live in stores you control rather than in Billet: workouts Billet wrote to Apple Health remain in the Health app (delete them there), and files you exported yourself remain wherever you saved them.
• Retention — raw second-by-second heart-rate samples are automatically deleted after 90 days. Per-set summaries derived from them are kept with your workout history so your training log stays intact.
• Lock screen — showing live heart rate on the lock screen is optional and can be turned off in the app.
• Apple Health (iOS) — HealthKit access is opt-in per data type through iOS permissions and can be revoked any time in Settings → Health → Data Access & Devices.
• Health Connect (Android) — access is opt-in per data type and can be revoked any time in Settings → Security & privacy → Health Connect → App permissions. Revoking it stops Billet reading new data immediately.

Data security

Billet's database lives in the app's private sandbox, protected by your device's encryption. Because there is no server, there is no server to breach.

Children

Billet is not directed at children and does not knowingly collect information from them. Where a minimum age applies to app or health-data use, it follows the higher of the applicable local requirements.

Changes

If a future version of Billet ever adds an online feature, this policy will be updated FIRST and the change will be called out in the app before any data leaves your device.

Contact

Questions: billetstrength@gmail.com