If you are using an older version of RadioKit, you may receive the following error when building your app:
Undefined symbols for architecture x86_64:
"_OBJC_CLASS_$_RadioKit", referenced from:
objc-class-ref in AraRadioAppDelegate.o
ld: symbol(s) not found for architecture x86_64
http://www.stormyprods.com/Libs/RadioKitLib-XCode5.zip
Simply replace the RadioKitLib in your project with these new files and your project should build without any issues.