Abstract: A parent mobile device sends a communication to a child mobile device, such as a phone call or an SMS message. The child device has an application installed which responds to the communication by determining whether receipt of the communication satisfies a mobile-device-lock-down criteria. When the communication satisfies the lock down criteria, the mobile device selectively limits functionality of the mobile device based on the determination. A child using the mobile device may attempt to unlock the device, for example, by returning a phone call to the parent device. When an attempt is made to unlock the mobile device, the application determines whether the attempt satisfies a mobile-device-unlock criteria. The application selectively restores functionality of the mobile device based on the determination of whether the attempt satisfies the mobile-device-unlock criteria.