21. The non-transitory computer-readable medium of claim 20 , further comprising executable instructions operative to cause the at least one processor of the mobile device of the enrollee to: record, using a global positioning system (GPS) receiver on the mobile device of the enrollee, a GPS location of the mobile device of the enrollee.
22. The non-transitory computer-readable medium of claim 21 , wherein the GPS location is recorded between receiving the first alert and receiving a second alert requiring the enrollee to perform a second check-in.