Google’s Android mobile operating system has a powerful app permission system that forces app developers to mention the exact permissions they require. By default, it is a Take-it-or-Leave-it situation, which means you can choose to install the app, granting all those permissions or simply, not install it. But, controlling these permissions as a user is possible, and there are apps that make it easier for you to control each single permission you grant to an app. One of the popular apps is App Ops that allows you to block permissions to individual apps that do not have anything to do with the main function of the apps.
Source: https://thehackernews.com/2015/06/android-permission-manager.html