Terms of Use

Last updated: September 2026 · Apple requires a functional Terms of Use (EULA) link for apps offering auto-renewable subscriptions.

Before you publish: If you do not want to maintain your own EULA, you may instead use Apple’s Standard End User License Agreement and link to it from App Store Connect. If you keep this custom one, have it reviewed — consumer-contract terms in Germany are strictly regulated (§§ 305 ff. BGB).

1. Agreement

These terms govern your use of the Spline iOS app and this website. By installing or using Spline you accept them. Spline is provided by Maximilian Herold (see Impressum).

2. What Spline is — and is not

Spline is an informational fitness and wellbeing tool. It is not a medical device under Regulation (EU) 2017/745, and it does not diagnose, treat, cure or prevent any disease. Biological-age estimates, readiness scores and laboratory interpretations are statistical surrogates with wide individual uncertainty, derived from published research and clearly cited in the app. They are not a substitute for professional medical advice. Always consult a physician before acting on anything you read in Spline, and never delay seeking medical care because of it.

3. Free version and Spline Pro

The core of Spline is free and stays free: daily readiness and its drivers, the HRV gate, sleep, recovery, training load, the workout and strength logs, the food log, the starting training plan, widgets and the Apple Watch app, every citation and formula, and full export of your own data as JSON or CSV.

Spline Pro is an optional auto-renewable subscription which additionally unlocks:

  • Biological age — the wearable estimate of the age your vitals read as, with the years each factor adds or subtracts
  • Bloodwork and lab import — lab PDF and photo import, PhenoAge, ApoB and Lp(a) analysis, change significance tested against the Reference Change Value, and the peptide effect tracker
  • Experiments and correlations — the N-of-1 engine with effect sizes, bootstrap confidence intervals and false-discovery-rate correction, and automatically found habit patterns
  • Adaptive planning — race-aware periodization and strength progression targets
  • The monthly review
  • Ask Spline and shortcuts — answers to questions about your own data, and typed sentences turned into logged sets or a routine

4. Subscription terms

  • Price: €3.99 per month or €34.99 per year, including VAT. Prices in other regions are set by Apple’s pricing tiers and shown before purchase.
  • Introductory offer: new subscribers to the monthly plan pay €0.99 for their first month, after which it renews at the regular monthly price unless cancelled. Apple allows one introductory offer per Apple ID for this subscription; eligibility is decided by Apple and shown before you buy.
  • Renewal: the subscription renews automatically at the end of each period unless cancelled at least 24 hours before it ends.
  • Cancellation: manage or cancel at any time in your Apple ID settings — Settings › [your name] › Subscriptions. We cannot cancel it for you, because Apple, not we, is the seller.
  • Refunds and withdrawal: purchases are made from Apple, so statutory withdrawal rights and refunds are handled by Apple through reportaproblem.apple.com.
  • If a subscription lapses: Pro features lock, but nothing you already recorded is deleted, and export stays free and available.

5. Your data

Your health data remains on your device and belongs to you. See the Privacy Policy. You are responsible for creating your own backups; because we hold no copy, we cannot restore data lost with a device.

6. Acceptable use

Do not reverse-engineer, resell or redistribute the app except as permitted by mandatory law, and do not use it in a way that breaks applicable law or Apple’s App Store Terms.

7. Liability

Spline is provided “as is”. To the extent permitted by law we exclude liability for slight negligence, except for injury to life, body or health, and except where liability is mandatory under the German Product Liability Act or arises from breach of an essential contractual duty — in which case liability is limited to foreseeable, contract-typical damage. Nothing here limits your statutory consumer rights.

8. Changes and governing law

We may update these terms; material changes will be announced in the app or on this page. German law applies, with the mandatory consumer-protection provisions of your country of residence remaining unaffected.