In a context of global insecurity, governments set up mass-surveillance programs. While some people have spoken out against, the majority continue to dangerously expose their private life on various social networks. When talking about mass surveillance systems, most people imagine expensive programs and backdoors implemented together with vendors and constructors. While this might be right, another question can be asked: Can people's widespread uses be turned against themselves? States and agencies have a lot of money to buy and develop complete solutions to track people but, unfortunately, we don't have that money. Instead, we will present how to track someone with a cheap -but not complete- solution. We will focus on a famous Android GPS-based dating application. This application's purpose is to notify the user when he's crossing or have crossed the way of people matching his preferences. Using only the initial specifications and features of the application, we will explain how to turn it into a GPS tracker.