Privacy policy

Draft · last updated 3 November 2026

Stren is an app for tracking your strength training. We collect as little as possible and never sell your data.

What stays on your phone?

Your workouts, routines, measurements and settings are stored on your own phone. Without an account, none of it leaves your device.

With an account

If you sign in (with email, Apple or Google) we keep a copy of your training data and preferences, so you get them back on a new phone. This is stored with our hosting provider Supabase and secured so that only you can access your own data. You can delete your account and all your data in the app at any time.

Apple Health and Health Connect

Only if you allow it, we write workouts to Apple Health or Health Connect and read data such as your body weight, height and past workouts. We use this data only inside the app and never for advertising.

Purchases

Payments go through the App Store or Google Play. We never see your payment details. We use RevenueCat to recognise your subscription.

Feedback

If you send feedback in the app, we store your message together with the app version, device type and language so we can fix problems. If you are signed in and say we may contact you, we can link your message to your account to reply.

Waitlist

If you join the waitlist on the website, we store your email address, whether you use iPhone or Android, whether you want to be an Android tester and the language of the page. We only use this to tell you when Stren is available (and, if you want to test, to invite you to the test). We share it with no one. Want to be removed? Email us and we delete your address.

Your rights

You can always view, export or delete your data. Questions? Emailsiebe-vaes@live.nl.