Privacy Policy

Last updated 16 September 2026

This Privacy Policy describes how Tropolin Labs LLC ("Sixteen", "we", "us" or "our") handles personal information when you use the Sixteen application, the website sixteen.life, and any related services (together, the "Services").

The short version

Your health data is read on your phone and scored on your phone. It is not sent to our servers unless you turn on backup or sync, and it is never used for advertising and never sold.
Screen time data (which apps you use and for how long) never leaves your phone. Apple's rules require this and we follow them.
Our servers hold your account, your purchase status, your journal and coach conversations if you use them, and basic usage and crash data.
You can export or delete everything from Settings inside the app, or by emailing legal@tropolinlabs.in.

1. What we collect

Account information. When you create an account we collect your name, email address, and a sign in identifier from Sign in with Apple or the sign in method you choose. You can also use Sixteen as a guest without an account; then we hold only a device identifier.

Health Information. With your permission, the app reads data from Apple Health (including data written there by an Apple Watch or other apps) and directly from a WHOOP strap over Bluetooth: heart rate, heart rate variability, resting heart rate, respiratory rate, sleep, workouts, active energy, steps and similar measurements. From these the app computes sleep, recovery, strain and stress scores. This data is processed and stored on your device. It is transmitted to our servers only if you turn on backup or cross device sync, in which case it is encrypted in transit and at rest. You can revoke Health access at any time in your device's Settings.

Screen time data. To score your screen time and to block apps on the schedules you set, the app uses Apple's Screen Time and Family Controls frameworks. Apple designs these so that app usage data is available only on the device. We do not receive which apps you use or for how long, and we cannot see the list of apps you chose to block.

Content you enter. Journal entries, logged meals and meal photos, workouts you log, and messages you send to the in app coach.

Purchase information. Whether you have lifetime access or an active subscription, the product, price and dates. Payment is processed by Apple (or by our web payment processor for purchases on the website). We never see your card number.

Device and usage data. Collected automatically when you use the Services: device model, operating system version, app version, language, country, IP address, crash reports and diagnostic logs, which screens and features you use and when, and, if you arrived through an ad or a link, the campaign that referred you. Location is derived from your IP address only, except when you use the outdoor activity feature, which uses precise GPS on the device to draw your route and is stored with that activity.

Support and correspondence. What you send us when you contact us.

All information you give us must be accurate, and you should tell us if it changes.

2. How we use it

To provide the Services: read your wearable, compute your scores, run your screen time rules, sync your account.
To answer your coach questions. Your message, together with the parts of your recent data needed to answer it, is sent to our servers and to an AI model provider under contract with us to generate the reply.
To recognise foods in meal photos you choose to log, using an image recognition service under contract with us.
To manage your account, purchases and subscription status.
To send service messages about your account, purchases, or changes to these terms, and, with your consent, product news you can opt out of at any time.
To keep the Services secure, prevent fraud and abuse, and fix bugs.
To understand how the Services are used, in aggregate, so we can improve them, and to measure whether our advertising works.
To comply with the law and respond to lawful requests.

We do not use Health Information or screen time data for advertising, marketing, data mining or profiling unrelated to the health and screen time features you asked for, and we do not sell it. Apple Health data is used only to provide health and fitness features, consistent with Apple's HealthKit terms.

3. Legal bases (EEA, UK and Switzerland)

Where data protection law requires a legal basis, we rely on: performance of a contract to provide the Services you signed up for; consent for Health Information, screen time controls, precise location, push notifications and marketing, which you can withdraw at any time; legitimate interests in securing, supporting and improving the Services and measuring our advertising, balanced against your rights; and legal obligations where we must keep or disclose data.

4. Who we share it with

We do not sell personal information and we do not share it for cross context behavioural advertising. We share it only with:

Service providers working under contract for us and only for the purposes above: cloud hosting for our servers and website, purchase and subscription management, crash reporting and product analytics, attribution and advertising measurement, email delivery, an AI model provider for the coach, and an image recognition service for meal photos. At the time of writing these include Apple, RevenueCat, AppsFlyer, Mixpanel, Meta (attribution only), Heroku, Vercel, Stripe for web purchases, and Google Workspace for email.
Apple and the App Store for purchases, and Apple Health and Screen Time on your device as described above.
Authorities where the law requires it or to protect the rights, property or safety of any person.
A successor if we merge, are acquired or sell assets, in which case this policy continues to apply to your information.
Anyone you direct us to, for example if you export your data and send it somewhere.

5. International transfers

Our servers and service providers are located in the United States and other countries. If you are outside the United States, your information will be transferred there. Where the law requires it, we use recognised safeguards such as standard contractual clauses.

6. How long we keep it

We keep your information for as long as you have an account, and for as long as needed afterwards to meet legal, tax or accounting obligations, resolve disputes and enforce our terms. Health Information stays on your device and is removed when you delete the app or revoke access. Backups and synced data are deleted when you delete your account, with copies in backup archives removed on the archive's normal cycle. Aggregated data that no longer identifies you may be kept.

7. Security

We use technical and organisational measures appropriate to the sensitivity of the data, including encryption in transit and at rest for anything that leaves your device and on device processing for health and screen time data. No system is completely secure, so we cannot promise that unauthorised parties will never defeat these measures. Keep your device passcode and account credentials private.

8. Your rights and choices

Everyone. From Settings inside the app you can export your data and delete your account and its data. You can revoke Health, Screen Time, location and notification permissions in your device's Settings. You can unsubscribe from marketing email with the link in any message. You can email us to access, correct or delete your information, or to ask a question.

EEA, UK and Switzerland. You have the right to access, rectify, erase, restrict or object to our processing of your data, the right to data portability, and the right to withdraw consent at any time without affecting earlier processing. You can also complain to your local data protection authority.

California. You have the right to know what personal information we collect, use and disclose, to request its deletion or correction, to opt out of sale or sharing (we do neither), and not to be discriminated against for exercising these rights. In the last twelve months we have collected identifiers, account and purchase information, device and usage information, Content you enter, and, on your device only, health and screen time information. We disclose information to service providers only for the business purposes above. You may use an authorised agent, and we may ask for proof of the authorisation. Under California's "Shine the Light" law you may also request the categories of information, if any, shared with third parties for their direct marketing, which we do not do.

We will verify requests by matching them against information we hold, and respond within the time the law allows. Email legal@tropolinlabs.in.

9. Children

The Services are not directed at children under 13, and we do not knowingly collect personal information from them. If you believe a child under 13 has given us information, contact us and we will delete it. Users under 18 should use the Services with a parent or guardian's permission.

10. Do Not Track

No uniform standard for Do Not Track signals has been adopted, so we do not respond to them. We will update this policy if that changes.

11. Changes to this policy

We may update this policy from time to time. The date at the top shows when it last changed. For material changes we will notify you inside the app or by email before they take effect.

12. Contact

Tropolin Labs LLC. Email legal@tropolinlabs.in