1. A computer implemented method performed by a mobile device, comprising: receiving, on the mobile device, a request for configuring a geographic region, the geographic region being associated with an application program of an application subsystem of the mobile device to be invoked when the mobile device determines that it has entered into the geographic region; in response to the request, configuring the geographic region through an application programming interface, the configuring including specifying one or more first call parameters according to a first calling convention defined by the application programming interface, where at least one first call parameter specifies a center of the geographic region; in response to configuring the geographic region, registering, on the mobile device, identifiers corresponding to one or more wireless access gateways with a location monitoring program on the mobile device; in response to registering the identifiers, placing, by the mobile device, the application program in a standby mode and suspending components of the application subsystem; monitoring, using a baseband subsystem of the mobile device and the location monitoring program, a current location of the mobile device with respect to the one or more wireless access gateways, the location monitoring program includes comparing the registered identifiers of the one or more wireless access gateways with a location of the mobile device via the baseband subsystem of the mobile device; in response to the monitoring, determining, based upon the comparing the registered identifiers of the one or more wireless access gateways with a location of the mobile device via the baseband subsystem of the mobile device, that the mobile device has entered the geographic region; in response to the determining that the mobile device has entered the geographic region, notifying the application subsystem, by the location monitoring program on the mobile device, that the application program is to be invoked; and in response to notifying the application subsystem, invoking the application program by moving the application program from the standby mode to an active mode on the mobile device.