From Xojo Documentation
Used to indicate when your app will need access to the device's location.
|Always||You are requesting that the OS update your app on the device's location any time it changes.|
|AppInUse||You are requesting that the OS update your app on the device's location only when your app is in the foreground.|
Updates to the device's location cause the LocationChanged event to be called. Always receiving updates uses more battery than receiving them only when your app is frontmost.
Mobile projects on iOS.