DescriptionSeveral studies have examined Android apps’ use of permissions from a security point-of-view. However, privacy has been an increasing concern with the increasing number of apps and most users are still not aware of several privacy-intruding permissions. This research investigates a dataset of permissions for over 610,000 apps existing on the Google Play Store on how they can impact users of smartphones. The objective is to better understand the patterns in permissions from a users’ perspective. We report findings on thousands of reputed apps using users’ coarse or exact location. About 70% of such apps were free and the major categories were Entertainment and Games. We observe more than 90% positive correlation between the ratings and such permissions. We also analyze device-intrusion where few apps ask for permissions to let the app run in the background, tweak with hardware and deplete energy using rich-media ads. For example, several apps in News & Magazines category were found to consume energy for downloading even when the device is in sleep mode. More than 20,000 free apps were found to receive packet data anonymously. The thesis concludes with discussion on implications obtained by employing k-modes algorithm to cluster dangerous and safe apps