You may meet the problem when you use iOS 7 + xCode 5 to build your project with ShareKit.
The iPhone simulation build can work, but when you switch to iPhone target, the xCode 5 will report "linking error, Undefined symbols for architecture arm7 ......".
The Problem mainly is unsuccessful build of "libGTLTouchStaticLib.a".
the solution: quite xcode 5, open the GTL.xcodeproj, make a build for simulation and iOS target.
and check the "libGTLTouchStaticLib.a" generated, then go back to your project, click "Product"->"Clean", and "Build" it again.
this should be a XCode 5 problem.
