This Privacy Policy explains what data Knurl collects, why we collect it, and the choices you have. Knurl is a strength-training app that runs on Android and in the browser, operated by Knurl Fit LLC ("Knurl", "we", "us"). We built it to be useful to the person lifting, not to profile them.

The short version

Your workout data lives on your device first. The cloud is a backup that syncs when you are online.
We do not run behavioral analytics, advertising trackers, or sell your data.
Cloud data is scoped to your account so only you can read it.
You can export everything as CSV or JSON, and you can delete your account from inside the app.

What we collect

Data you create

Workout logs. The exercises, sets, weights, reps, and effort ratings you record.
Training inputs. Optional readiness ratings, bodyweight, equipment profiles, and program choices.
Imported files. If you import a Garmin FIT file, we process the heart-rate and timing data it contains so we can overlay it on your session.

Account data

You can use Knurl anonymously. If you choose to create an account, we store an account identifier and, depending on your sign-in method, your email address. Sign-in is offered through email, Google, and Apple.
When you sign in, the chosen provider authenticates you. We receive a basic identifier from that provider and do not receive your password.

Technical data

Minimal data needed to keep the app working and synced, such as sync timestamps and error states. We do not maintain advertising profiles or third-party tracking pixels.

Payment data

Knurl Pro is billed through Google Play. Google processes your payment and is the merchant of record. We receive your subscription status from Google. We never see or store your full payment card details.

How we use your data

To run the core app: store your logs, estimate your strength, and prescribe your training.
To sync your data across your devices and back it up.
To provide and manage your subscription.
To respond to support requests you send us.
To keep the service secure and fix problems.

We do not use your training data to advertise to you, and we do not sell it.

Where your data is stored

On your device. Knurl is offline-first. Your data is written to local storage on your device so the app works without a connection.
In the cloud. If sync is active, your data is stored in a managed Postgres database (Supabase) with row-level security so each account can only access its own data.

Service providers

We share data only with the providers needed to run Knurl:

Supabase for authentication and cloud database storage.
Google Play for app distribution and subscription billing.
Sign-in providers (Google, Apple) when you choose to sign in with them.

These providers process data on our behalf under their own terms. We do not sell or rent your personal data to anyone.

Your choices and rights

Export. Export your full history as a CSV workbook or a JSON snapshot at any time from the app.
Delete. Delete your account and associated cloud data from inside the app.
Use anonymously. Use core logging without creating an account.
Access and correction. Contact us to request access to or correction of your data.

Depending on where you live, you may have additional rights under laws such as the GDPR or CCPA, including the right to access, correct, delete, or port your data, and to object to certain processing. To exercise any right, email us at hello@knurl.fit.

Data retention

We keep your data while your account is active. When you delete your account, your cloud data is removed. Data stored locally on your device is removed when you delete the app or clear its storage.

Children

Knurl is not directed to children. You must be at least 18 years old to use Knurl. We do not knowingly collect data from anyone under 18. If you believe someone under 18 has provided us data, contact us and we will delete it.

International transfers

Your data may be processed in countries other than your own, including by the service providers listed above. Where required, we rely on appropriate safeguards for those transfers.

Changes to this policy

We may update this policy as the app evolves. When we make material changes, we will update the date above and, where appropriate, notify you in the app.

Contact

Questions about this policy or your data? Email hello@knurl.fit.

Knurl is operated by Knurl Fit LLC, a Missouri limited liability company.