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# sessionCompanionAppInstalledDidChange(_:)

Indicates a change to the companion app’s installed state.

```
optional func sessionCompanionAppInstalledDidChange(_ session: WCSession)
```

## Parameters

`session`

The session object with the changed companion app.

## Discussion

The system calls this method on the watchOS app’s session delegate when the user installs or uninstalls the iOS companion app. This is only valid on independent watchOS apps.

---

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