*For Android 6.0 and above:
Revoking permissions by category: Device Settings > Apps > More (Settings and Controls) > App Settings > App Permissions > Select the relevant permission > Choose to grant or revoke access
Revoking permissions per app: Device Settings > Apps > Select the app > Select Permissions > Choose to grant or revoke access

*For Android versions below 6.0:
Due to the nature of the operating system, it is not possible to revoke permissions by category. You can only revoke permissions by deleting the app. It is recommended to upgrade your Android version to 6.0 or higher.

*For iOS/iPadOS 11 and above:
Settings > Privacy > Select the relevant permission > Choose to grant or revoke access