A method, system, and medium are provided for monitoring a location of an object using a mobile device, including emitting from the mobile device a radio frequency (RF) signal that activates a radio frequency identifier tag (“RFID tag”) located within a broadcast area (the RFID tag being affixed to the object); receiving at the mobile device an RF signal generated by the RFID tag; determining that the RFID tag is registered among a set of RFID tags that are to be tracked; determining that the RFID tag is not located within the broadcast area; and emitting by way of the mobile device an alert that indicates that the RFID tag is not located within the broadcast area.