Unlike Windows Phone 8 OnSuspending is not fired when the app is suspended or terminated. As this is were I place my code to save app settings. In order debug I need to be able to fire OnSuspending.

To achieve this, in VS2015 click View > Toolbar > Debug Location. Then when I run my app, I click Lifecycle Events > Suspend.

Screenshot

OnSuspending does not fire on Windows Mobile 10 emulator