Many countries today have "country-centric mobile apps" which are mobile apps that are primarily used by residents of a specific country. Many of these country-centric apps also include a location-based service which takes advantage of the smartphone's API access to the smartphone's current GPS location. In this paper, we investigate how such country-centric apps with location-based services can be employed to study the diaspora associated with ethnic and cultural groups. Our methodology combines GPS hacking, automated task tools for mobile phones, and OCR to generate migration statistics for diaspora. As a case study, we apply our methodology to WeChat, an enormously popular app within China and among ethnic Chinese worldwide. Using WeChat, we collect data about the Chinese diaspora in 32 cities. The combined data provides interesting insights to the modern Chinese diaspora and how it has changed in recent years.