A plug-in module providing the functionality of a covert alarm and locator apparatus allows the module to be moved between various articles of footwear or other apparel, as desired, and it allows the module to be used for additional purposes, such as pet monitoring, or the inclusion within a golfer's glove having a display which shows the distance to the pin on a particular course. By modularizing the circuitry, it is fast, easy, and inexpensive for a parent to replace a child's footwear when the child needs a larger size. Further, there is no need to have numerous cellular phone or monitoring subscriptions, as they are all tied to a single, moveable module. In addition, traditional competitive apparel manufacturers can each supply units capable of receiving the module on a competitive basis, thereby extending the user's purchase and style options while still providing the benefits of having a covert alarm and locator apparatus, as described.