No reports from an iOS device (iPhone, iPad, and iPod) after being marked as missing
iOS applications can’t run without the user’s interaction. This means they won't run unless you tap their icon, and can't be lifted remotely. However, Apple does let some applications to run on the background, such as music players and maps. That's how Prey for iOS works its magic.
To ensure Prey will work on your iOS device, it is very important that the application is open and running on the background. This means, open and never manually killed. With this, even if the device is turned off and on again, Prey will be there and report when necessary.
For further information on this, please check the Recommended Settings for mobile devices with Prey.