Terms of Use

Last updated: October 28, 2026

These terms apply to the Musclr app and to Musclr Pro. Musclr is made by Tijn Knapen, Nederweert, the Netherlands ("we", "us"). By using Musclr you agree to these terms. If you got Musclr from the App Store, Apple's Standard Licensed Application End User License Agreement applies as well.

1. What Musclr is

Musclr is a workout tracker. It logs your training, builds a plan from your answers, and explains with 3D guides how an exercise loads a muscle. The numbers in the guides come from a 3D model of the human body: they show how a detail changes the work a muscle does, they are not a measurement of your body.

2. Train safely

• Musclr gives general information about training. It is not medical advice and it does not replace a doctor, physiotherapist or coach.
• Talk to a doctor before you start training if you have an injury, a medical condition, are pregnant, or are unsure whether training is safe for you.
• You train at your own risk. Use a weight you can control, warm up, and stop when something hurts.

3. Free and Pro

Logging, the rest timer, your history, your records and export are free, with up to 3 routines. Musclr Pro adds unlimited routines, every program, the 3D muscle guides and the weekly muscle report. What is free stays free: we never move a free feature behind Pro.

4. Subscriptions

• Musclr Pro is an auto-renewing subscription, monthly or yearly. The price is shown in the app before you buy and is charged to your Apple ID or Google account.
• Free trial: the monthly plan starts with a free trial for new subscribers. When the trial ends, the subscription starts and you are charged, unless you cancel at least 24 hours before the trial ends. We remind you a day before.
• Renewal: the subscription renews at the end of each period at the same price, unless you turn off auto-renew at least 24 hours before the period ends.
• One-time offer: a yearly plan at a lower price may be offered once. It renews at that same price.
• Cancel or switch in the subscriptions of your App Store or Google Play account. Pro stays until the end of the period you paid for.
• Refunds are handled by Apple or Google under their own policies.
• If a price changes, the store tells you in advance, as its rules require.

5. Your data

Your workouts and answers are stored on your phone, not on our servers. You can export them at any time. You are responsible for your phone's backups. How we handle data is described in the Privacy Policy.

6. Using Musclr

• You may use Musclr for your own, non-commercial training.
• The app, its 3D guides, videos, texts and design belong to us. You may not copy, resell or redistribute them, or take the app apart, except where the law allows it.
• Do not use Musclr in a way that breaks the law or harms the app or other people.

7. Liability

We build Musclr with care, but we provide it as it is and cannot promise it is always free of errors or available. To the extent the law allows, we are not liable for injuries, lost data or indirect damage from using Musclr. Nothing in these terms limits rights you have under consumer law that cannot be waived.

8. Changes

We may update these terms when the app changes. The date at the top shows the latest version. If a change matters to you, we will tell you in the app.

9. Law

Dutch law applies to these terms. If you live in the EU, you also keep the protection of the law of the country where you live.

10. Contact

Questions about these terms: support@musclr.app.