---
title: "sessionCompanionAppInstalledDidChange(_:)"
framework: watchconnectivity
role: symbol
role_heading: Instance Method
path: "watchconnectivity/wcsessiondelegate/sessioncompanionappinstalleddidchange(_:)"
---

# sessionCompanionAppInstalledDidChange(_:)

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

## Declaration

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

## Parameters

- `session`: The session object with the changed companion app.

## Discussion

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.

## See Also

### Managing State Changes

- [sessionWatchStateDidChange(_:)](watchconnectivity/wcsessiondelegate/sessionwatchstatedidchange(_:).md)
- [sessionReachabilityDidChange(_:)](watchconnectivity/wcsessiondelegate/sessionreachabilitydidchange(_:).md)