One of the hidden features in Android 4.3 Jelly Bean was App Ops, that allowed users to view and deny various permissions to applications. The feature was hidden by default, and required the use of an app called App Ops (or custom ROMs) which displayed the hidden interface.
When KitKat was released, many people assumed Google killed App Ops since the hidden feature was nowhere to be found in teardowns. As it turns out, App Ops is still present in KitKat, but just smartly hidden. If you are running Android 4.4 KitKat on your device, use the aptly named App Ops from the Lars Team to gain access to this hidden feature. The app does not require root access, and even includes all the updated permissions that Google has introduced in KitKat.
Using App Ops, you can deny apps from holding a wakelock in the background, access your call logs, location record audio and much more. The best part about denying permissions using App Ops is that it makes sure that the apps don’t misbheave and work just as intended. If you are paranoid about apps stealing your personal data, App Ops is your answer.
