Terms of Service

Stacks is a free, personal workout and nutrition tracker. By creating an account, you agree to the terms below. They're written to be read, not skipped.

Stacks is operated by Aurélien Durier (an individual), based in France. Contact details are at the bottom of this page.

You need to be at least 16 years old to create an account. You're responsible for keeping your password safe and for what happens under your account. If you suspect unauthorized access, change your password and let us know.

One person, one account. Don't share your credentials.

Stacks is provided for personal, non-commercial use. You may use it to log your own meals, workouts, and bodyweight, and to view what you've logged. You may not:

• —Reverse-engineer, scrape, or automate the app or its API for purposes other than personal use.
• —Resell access, or expose Stacks data to third parties without their consent.
• —Use Stacks to harm yourself or others, or to bypass medical advice — see the disclaimer below.
• —Attempt to disrupt the service, gain unauthorized access, or upload malicious content.

You own everything you log into Stacks. We store it so the app can show it back to you, and we treat it according to our Privacy Policy.

You can export all your data from Settings → Account & data → Download my data, and you can permanently delete your account and its data from Settings → Account & data → Delete account.

Stacks is free for personal use. If we ever introduce paid features, we'll notify you and ask for your explicit consent before charging — using the free version will always remain possible unless we sunset it with reasonable notice.

Stacks is a tracker, not a medical device or a coach. The targets it computes (calories, macros) are estimates derived from a public formula (Mifflin-St Jeor) and your inputs. They're a starting point, not a prescription.

Don't use Stacks as a substitute for advice from a qualified health professional. If you have a medical condition, an eating disorder history, or specific dietary needs, consult a doctor or dietitian before relying on the app's suggestions.

We aim to keep Stacks available, but we don't promise zero downtime. Maintenance, infrastructure issues, or external incidents can interrupt the service. We're not liable for losses caused by such interruptions.

You can delete your account at any time from the app. We may suspend or close accounts that violate these terms or harm the service or its users. Where possible, we'll warn you first.

Stacks is provided "as is." To the extent permitted by law, we're not liable for indirect or consequential damages arising from your use of the app, including data loss, missed targets, or health outcomes. This doesn't exclude liabilities that French law doesn't allow us to disclaim (e.g. gross negligence, fraud).

If we materially change these terms, we'll notify you in the app and update the effective date above. Continued use after the change means you accept the new version. If you disagree, you can delete your account.

These terms are governed by French law. Disputes that can't be resolved amicably fall under the jurisdiction of the courts of the operator's residence, unless mandatory consumer law assigns them elsewhere.