We present APPropriate-a novel mobile design to allow users to temporarily annex any Android device for their own use. APPropriate is a small, cheap storage pod, designed to be easily carried in a pocket or hidden within clothing. Its purpose is simple: to hold a copy of the local content an owner has on their mobile, liberating them from carrying a phone, or allowing them to use another device that provides advantages over their own. Picking up another device when carrying APPropriate transfers all pertinent content to the borrowed device (using local no-cost WiFi from the APPropriate device), transforming it to give the impression that they are using their own phone. While APPropriate is useful for a wide range of contexts, the design was envisaged through a co-design process with resource-constrained emergent users in three countries. Lab studies and a subsequent deployment on participants' own devices identified key benefits of the approach in these contexts, including for security, resource sharing, and privacy.