Social networks provide a growing mean of communication that still preserves our human social interaction. Due to the widespread use of mobile devices, and the vast development of applications targeting these platforms, people tend to use their smartphone or tablet as the main way to make that interaction. Furthermore, applications developed to these devices are fostering the use of contextual information, such as the location of the user. In this way, this article describes a model for a spontaneous social network targeted at mobile devices. In our proposal, named Mingle, the social network is spontaneous, i.e., involves only people who are physically present in a specific location. Besides presenting the model, we show a developed prototype using Android-based
devices. We evaluated Mingle employing two strategies. The first evaluation consisted of a performance evaluation of the server. The second assessment focused on usability, regarding  effectiveness, efficiency and satisfaction of users in using Mingle. The results were encouraging and show the potential of deploying Mingle in real situations.

Social Network Analysis and Mining