My problem adding a new service Windows Phone 8.1 but I can't see to tab, 8.1 doesn't add the service?
This is a known issue with Windows Phone 8.1 Store apps. See the sticky post on the official Developing for Windows Phone forum on MSDN: WCF Add Service Reference Not Supported for Windows Phone 8.1 XAML Applications
Windows Phone Store apps in Windows Phone 8.1 do not support the System.ServiceModel namespace generated by the Add Service Reference menu.
The general recommendation is to expose a REST endpoint from the service rather than a WCF service.
If you cannot add a REST endpoint and must use WCF then either write a Silverlight app instead of a Windows Runtime app or you'll need to write your own code to wrap the WCF conversation.