Windows Phone 8.1 GDR 2 came up with an update which allows you to control app permissions in your phone. This feature will allow you to define what hardware / phone feature can an app access.
- Navigate to settings.
- Search / Scroll to app permissions.
- Tap on any permission listed.
- You can universally turn on / off that permission for all the apps.
- Or if you wish to restrict at app level, you may do so in the apps listed below
Currently you can define permissions for the below.