isla

Privacy Policy

Updated 2026-10-11.

Where your log is kept

Isla writes what you log into its own storage on your iPhone. You never make an account with Isla. Tundra Industries runs no server that holds your cycle data, so there is nothing of yours for us to read, sell, lose or hand over.

Isla's label on the App Store says "Data Not Linked to You: Usage Data (Product Interaction)". Nothing is used to track you and nothing is linked to you. The app ships with no outside analytics, crash reporting, attribution or ad SDK.

Apple Health

Health sync is off until you switch it on. Then Isla reads and writes Cycle Tracking samples in Apple Health on the same iPhone. Samples read from Apple Health are never sent to Tundra or to anyone, and never used for advertising or data mining. Isla 1.0 does not put health data in iCloud.

The app events Tundra receives

Isla reports a handful of events to Tundra Signals, analytics that Tundra Industries runs itself: the app was opened, setup was finished, a day was logged, the Pro screen was shown or closed, a purchase or restore happened, a widget was added. These events never include anything you log: no dates, flow, symptoms, moods, notes, tests or modes. A filter inside the app drops any event that would.

  • app opened
  • setup finished
  • a day logged
  • Pro screen shown
  • purchase

Each event is tied to a random install number that Isla makes on first launch. It is not your Apple Account, it is not an advertising ID, and it is never matched with data from other companies. Apple's App Privacy wording for this is Usage Data, Product Interaction. Delete everything in Isla and the app also asks Tundra to erase the events under that install number.

Buying Isla Pro

The App Store takes the payment. Isla learns only whether this Apple Account owns Isla Pro; card numbers and billing details stay with Apple.

Exporting and erasing

Settings, Your log, Export a copy writes your whole log as JSON or CSV for you to keep or move. Delete everything in the same group erases every logged day on this iPhone at once. What Isla wrote to Apple Health stays there until you remove it in the Health app.

Writing to us

Privacy requests go to isla@tundra.industries. We answer from that address.