Android is an open source mobile operating system contributed by Google. In general, Google Play is the most secure place to download the mobile applications for Android system. [1] Products from this website are surely safe promised by Google Company. But there are many other third-party app stores around the world offering similar software. One incentive for them is that the security policy on different platforms varies a lot, and Android developers are free to distribute apps in any intended ways, which leads to a certain risk in the assorted stores such as malware. Therefore, it is crucial to know which application store can be trusted from the various app stores. [2] To support our research, a tool named APK Safety Test is developed to compare the APK files from different application stores with the version on Google Play. In this study, nine stores around the world are chosen and 20 various applications from them are checked in real-time by using the tool. From this research, people can learn the different risk how can be detected. Furthermore, this paper analyzes the result of risks how to affect the applications. Keywords: Android application, Android Stores, APK files, Risk