Disclosed are various embodiments for flexible, low-cost tracking devices capable of seamless indoor and outdoor tracking transitions. A tracking device may comprise, for example, circuitry combined with one or more transceivers on a flexible substrate. At least a portion of the circuitry may be printed using a conductive medium, such as nanoparticle ink. The tracking device may be configured to localize the tracking device via GPS or an alternative localization strategy based on a determination of whether GPS communication is available.