Write an Android application

Need to have 2 client interface in Android Tablet Device. Both app need to be locked and user are not allow to exit to home screen unless admin to exit. Device 1 is to have linking to a local webserver, grap data from the mysql, able to detect the distance with iBeacon, embedded a surveillance CCTV when the device had reach a certain distance with the iBeacon. Device 2 is basically is for billing when the device 1 hits BILL. able to print receipt.