in XCode (for iOS 8) using Swift language, there is no Service Reference folder to add for NAV Web Service
Understand iOS 8 (Swift) does not have Web service referen
If you want to connect to the Dynamics NAV webservices, you should change the setting "ServicesUseNTLMAuthentication" in:
This setting is located in the CustomSettings.config file the NAV service folder.
You can use SoapUI for testing, as explained in the answer above.