Privacy Policy — Waterline

Last updated: 15 August 2026

Waterline does not collect your data. There is no account, no server, and no analytics. Everything you log stays on your device and in your own iCloud — never on any server of ours, because we do not have one.

This policy describes what the app does. It is written to be checkable against the app’s behaviour rather than to be broad enough to cover anything we might do later.

What is stored, and where

Waterline stores the drinks you log, your daily goal, your containers, your unit preference and your reminder schedule in the app’s own container on your device.

That container is also mirrored to your private iCloud database, so the same log appears on your other devices signed in to the same Apple Account. This is what makes a new iPhone open with your history already in it. Three things are true of that copy and worth stating plainly:

• It is in your iCloud, in the private database of the app’s container. It is not on a server we run, and we have no key, no console and no way to read it.
• It is not a backup we take. It is Apple’s sync, using your storage and your account, and it obeys whatever you have set for Waterline under Settings › your name › iCloud.
• If it cannot be reached — no iCloud account, or sync turned off for this app — the app works exactly as before, entirely on the device. Nothing is lost and nothing is refused.

The app’s container is separately included in your device backup, iCloud or local, which is encrypted and controlled by Apple’s backup rather than by us.

The app also stores a small record in the device Keychain used to verify your Pro purchase offline. It contains no personal information.

What is not collected

• No account. There is nothing to sign up for and no way to.
• No analytics, telemetry, crash reporting or advertising. The app contains no third-party SDKs of any kind.
• No tracking. Waterline does not collect data used to track you across apps or websites, and shows no ads.
• No network requests, except to Apple’s own services as described below.

Apple Health

Waterline can use Apple Health in two separate, independent ways. Both are optional and off until you turn them on, each asks for its own permission, and you can decline either and keep using the app — nothing about logging drinks, reminders or your goal depends on Health.

Writing your drinks to Health

If you turn on Sync with Health, Waterline writes each drink you log to Apple Health as a water (dietaryWater) sample, so your water appears alongside the rest of your data.

If you delete a drink in Waterline, the app deletes the matching Health sample. Turning the sync off stops new samples being written; samples already written stay yours, in Health, until you remove them there.

Reading metrics to estimate what you need

If you turn on the hydration estimate, Waterline reads the following from Health to calculate how much water to suggest:

Read	Used for
Body mass	the size-based part of the estimate
Active and resting energy	how active your day has been
Workouts, heart rate, walking + running distance	estimating fluid lost to sweat
Resting heart rate	context alongside your intake
Sleep analysis	a note when you have slept unusually little
Date of birth, biological sex	inputs the published estimation equations require

What happens to that data: it is read from Health on your device, used immediately to compute the numbers you see, and held only in memory. Waterline does not copy it into its own storage, does not include it in the CSV export, and does not retain it after the app closes. Each time the estimate is shown, it is read fresh.

Applying to both

• Health data is never sent to us. Waterline has no server, makes no network requests, and contains no third-party code that could send it anywhere.
• Health data is never used for advertising or marketing, never shared, and never sold.
• The body, workout, sleep and heart-rate figures Waterline reads are not stored in iCloud. They are held in memory for the screen that shows them and read fresh next time.
• One exception, stated because it would otherwise be a surprise. If you use the one-time import to bring water you had already logged in Health into Waterline, those drinks become part of your Waterline log — and your Waterline log is mirrored to your own private iCloud like the rest of it. Nothing else read from Health is treated that way, and the destination is still your iCloud rather than any server of ours.
• You can change or revoke either permission at any time in the Health app under Sharing → Apps → Waterline, or turn the features off in Waterline’s own Settings.

Purchases

Waterline Pro is a one-time purchase handled entirely by Apple. The app receives only whether a purchase exists for your Apple Account. It never sees your name, payment details, or Apple Account credentials, and no purchase information is sent anywhere by us. Apple’s handling of your purchase is covered by Apple’s Privacy Policy.

Notifications

Reminders are local notifications, scheduled on your device by the app. Nothing is sent to a server, and notification text never contains anything you have typed. You can turn reminders off in the app, or revoke permission in iOS Settings.

The app does register with Apple’s push service, so iCloud can tell it when another of your devices has logged a drink. No message content is involved, no notification is shown, and nothing reaches us — the device token goes to Apple.

Export

The CSV export is produced on your device and written only to the location you choose in the system save dialog. Nothing is uploaded, and the app keeps no copy.

Children

Waterline collects no personal information from anyone, including children under 13.

Changes

If this policy changes, the date at the top will change with it, and material changes will be noted in the app’s release notes.

Contact

Questions about this policy: developer.cloud26@gmail.com