*First annual install.* This is the first time an app is installed by an account in the EU in a 12-month period. After each first annual install, the app may be installed any number of times by the same account for the next 12 months with no additional charge. A first annual install may result from an app’s first-time install, a reinstall, or an update from any iOS app distribution option — including the App Store, an alternative app marketplace, TestFlight, an App Clip, volume purchases through Apple Business Manager and Apple School Manager, and/or a custom app.

*One million free first annual installs.* Membership in the Apple Developer Program includes one million first annual installs per year for free for apps distributed from the App Store and/or alternative marketplaces.

*Fee for each first annual install over one million.* Developers will pay a Core Technology Fee of €0.50 for each first annual install over one million in the past 12 months.

Thanks, that's much clearer

If I reinstall an app 10 times over two years it’s 1.00.

That’s my guess.