So...
When you want to use core services ( core location, contacts, bluetooth etc ), you should ask user for permissions.
If you want this functionality, you should also include NS(Service)UsageDescription keys in Info.plist ( and in InfoPlist.strings for localization ).
// InfoPlist.strings
"NSLocationAlwaysUsageDescription" = "Used to <your choice>"When user wants to restrict access for apps to his information, he could turn off permissions in settings app.
So, when user opens settings app, he navigate to appropriate application and open it.
User sees list of settings.
Question
Is it possible to show user ( by default? ) all NS(Service)UsageDescription strings that had been shipped in app in settings?
It could be unclear for user ( user could forget ) that app uses certain service in case of something valuable.