There is Anti-Theft app using USB cable.
The app sounds alarms detecting the USB cable disconnection.
[How to use]
1. Start "Guided Access" 3 click home button after setting the "Guided Access" from Settigs-General-Accessibility-Guided Access"
2. Connect USB cable (Charging)
3. Push the center image to start detecting theft.
4. The app play alarms if you disconnect earphone jack (pull out the jack)
5. You can stop the alarms after input the password.
Simple for Anti-Theft.
Keep your phone!