Privacy Policy

Last updated: September 22, 2026

WeightPilot is a mobile app and website operated by Matthew Lloyd ("WeightPilot", "we", "us", "our"). This policy explains what information WeightPilot collects, why it is collected, who processes it for us, how long it is kept, and how you can delete it. It applies to the WeightPilot apps for iOS and Android and to www.weightpilot.com.

Information we collect

Information you provide

• Weight measurements that you enter or that come from a connected source. Each measurement has a date and time, and it may include a body fat percentage.
• Profile information that the body model needs: birth year, height, and sex.
• Targets and settings, such as your target weight or body fat percentage, your preferred units, and your time zone.
• Account information, if you create an account: your email address, and the public keys of any passkeys you register. We never receive your passkey's private key or your device's biometric data.

Information from services you connect

• Withings. If you connect a Withings scale, we receive an authorization token and your Withings user ID from Withings. We then retrieve your weight and body composition measurements.
• Apple Health (HealthKit) on iPhone and Health Connect on Android. With your permission, WeightPilot reads your body weight (and body fat percentage, where available) and your daily active energy burned (active calories). We read this data only to add your weigh-ins and to improve the accuracy of your throttle and estimates. WeightPilot doesn't write any data to Apple Health or Health Connect. You can change or revoke these permissions at any time in the Health app or in Health Connect settings.

Information collected automatically

• Device and app information: a random identifier that the app creates for your device (so WeightPilot works without an account), the app version, and your platform.
• Push notification token from Firebase Cloud Messaging, so we can tell you when your throttle changes.
• Usage analytics: Google Analytics for Firebase records how the app is used, for example which screens are opened and which features are used, along with general device information such as model, OS version, and approximate country. Firebase Performance Monitoring records app start-up and network timing. We don't link analytics to your account, send it your weight or health data, or collect advertising identifiers.
• Server logs: our servers record basic request information, including IP addresses, for security and troubleshooting.

Information we calculate

WeightPilot uses your measurements and profile to calculate your throttle, your stable weight, your short-term weight (carb stores and fluid), body fat estimates, and projections toward your target. We store these results with your data.

How we use your information

• To provide the WeightPilot service: running the body model, calculating your throttle and estimates, and showing your history and progress.
• To sync your data across your devices and keep it when you reinstall the app, if you have an account.
• To send notifications you have allowed, such as throttle updates.
• To send sign-in codes and essential account emails. We don't send marketing email.
• To keep the service secure, prevent abuse, fix bugs, and improve the app. We use aggregate analytics for this.

Health data

Weight, body composition, activity, and profile data are sensitive, and we treat them that way:

• We use health data only to provide WeightPilot's features to you.
• We never sell health data. We don't use it for advertising, marketing, or data mining, and we don't share it with data brokers or other third parties, except the service providers listed below that process it on our behalf to run the service.
• Data read from Apple Health and Health Connect is used in accordance with Apple's HealthKit guidelines and Google's Health Connect permissions policy, including its Limited Use requirements. It isn't stored in iCloud, and it isn't used to train general-purpose AI models.
• We don't share your data with employers, insurers, or advertisers.

Who processes your data

We don't sell or rent personal information. These service providers process data for us under their own privacy and security terms:

We may also disclose information if the law requires it, to protect the rights, property, or safety of our users or others, or as part of a transfer of the service. If WeightPilot is transferred, this policy will continue to apply to your data.

Using WeightPilot without an account

You can use WeightPilot without signing in. Your data is then stored on our servers under a random device identifier instead of an account. If you later create an account on that device, your data moves into the account.

Retention and deletion

We keep your data while you use WeightPilot. You can delete it at any time:

• Delete your account in the app: Settings → Account → Delete Account. This permanently erases your account and all of its data from our database: measurements, targets, profile, activity, calculated results, push tokens, and connected-service authorizations. It also disconnects your Withings scale. Data on your device is removed too.
• Disconnect a service: you can disconnect Withings in Settings, and you can revoke Apple Health or Health Connect access in their settings at any time. This stops future imports. Measurements that were already imported stay in your history until you delete your account.
• By email: if you can't use the app, or you used WeightPilot without an account, email privacy@weightpilot.com and we'll delete your data.

Deleted data may stay in our encrypted server backups for a limited time, until those backups expire on our regular schedule. Analytics data is kept by Google according to our Firebase retention settings and isn't linked to your account.

Security

Data is encrypted in transit between the app and our servers. Access to our servers and database is restricted, and data cached on your device is kept in the app's private storage. No system is perfectly secure, but we work to protect your information and to limit what we collect.

Your rights

Depending on where you live, you may have the right to access, correct, export, or delete your personal information, to object to or restrict some processing, and to withdraw consent. You can see and edit most of your data directly in the app, and you can delete it as described above. For any other request, email privacy@weightpilot.com. We'll respond within 30 days and won't discriminate against you for exercising your rights. Where the GDPR applies, we process your health data based on your explicit consent, which you give when you enter it or connect a data source, and which you can withdraw at any time by deleting it. We process your other data as needed to provide the service you request. We store and process data in the United States.

California residents: we don't sell or share personal information for cross-context behavioral advertising, and we don't use sensitive personal information for any purpose other than providing the service.

Children

WeightPilot is intended for adults aged 18 and over, and it isn't directed to children. We don't knowingly collect information from children under 13. If you believe a child has given us information, contact us and we'll delete it.

The website

www.weightpilot.com doesn't use cookies, analytics, or advertising. Our servers log basic request information, as described above.

Changes to this policy

We may update this policy from time to time. We'll post the new version here and change the date above. If we make material changes, we'll notify you in the app before they take effect.

Contact

Questions about privacy? Email privacy@weightpilot.com. For help with the app, see Support.