Both the n-Stream and n-Serve applications have been tested extensively by Naim Audio before being submitted to Apple for approval for uploading to the Appstore. This means the apps should be stable. If you are having issues with the app please first ensure your firmware is completely up to date on your Apple device. If you#re stilling having issues please delete the application power down your Apple device power it up again and reinstall the application: this usually resolves any problems