Smartphones have the ability to communicate with other terminals through ad hoc connections. A variety of applications have been developed to exploit this ability. The authors have developed an Android OS (operating system) application (called "social DTN manager") that builds a DTN (delay, disruption, disconnection tolerant networking) among members of a social networking service (SNS) community using a community token. The members can exchange messages over this network. Control messages for building a DTN are forwarded to only those nodes that use the same community token in order to reduce flooding of message copies. When a source node sends a communication request to its destination node, they exchange control messages to establish a communication route. Relay nodes use these messages to create and hold routing information for these nodes in their routing tables. Thereafter, relay nodes can forward data messages based on their routing tables. This again reduces flooding of message copies. The social DTN manager incorporates these functions, Facebook Graph API and Google Nearby Connections API. The authors have installed it in Android terminals and confirmed that a social DTN can successfully be built using this application and that data messages can be exchanged between terminals via reactive routes.