E6B Slide Rule gathers no data about you — not your identity, not your location, not how you use it. There is no account and no server to send anything to.
The app has no reason to reach the internet, so it never does.
The app remembers the angle you last left the dial at, and when you left it there, so a setting survives putting your wrist down. Both are stored on the device, are discarded after 24 hours, and are never transmitted anywhere.
That is the whole of it. Deleting the app removes them.
The same claims appear in the app’s privacy manifest, which Apple checks at submission, and in its App Store privacy label — which is empty, because there is nothing to declare.
The app collects nothing from anyone, children included, and contains no advertising, no purchases and no links out to other services.
This page will say so, and the date at the top will move. Any version of the app that collected anything would also have to declare it in its App Store privacy label before it could ship.