A 'find my iPhone' app appeared on my sisters phone about a year ago. She never downloaded it herself and thought it must have come from an update. When she opened the app her Apple ID was already prepopulated. She has recently found out her husband has been having an affair for sometime and is now wondering if he has been tracking her using this app. I know that find my iPhone is available for all iPhones but I thought that to have the app you needed to actually download it rather than it being part of an update.