1. You must get a key in the Google Developer Center, and register it in the below function in APPDELEGATE.M file.
-(BOOL) Application: (UIApplication *) application didfinishlaunchingwithoptions: (Nsdictionary *) launchOptions {// Override point for customization after application launch. [Gmsservices provideapikey:@ "AIZASYD4UCHJBSOJMJNRQN_II6UEJJJ84KZUPNC"];
}
2. If during start up Google Map has below error in debug window, need to ADD-OBJC to Build Settings, linking Other Linker Flags.
2015-10-24 22:56:31.761 easyq[2510:176045] coredata:failed to load optimized model at path '/users/yanliyuan/library/dev eloper/coresimulator/devices/dfa41111-c50f-4c9b-8d01-dad0f38bc6b9/data/containers/bundle/application/ 9a82a689-5b32-4828-b54a-55112eb8be17/easyq.app/googlemaps.bundle/gmscachestorage.momd/storage.omo '
2015-10-24 22:56:31.788 easyq[2510:176045] coredata:failed to load optimized model at path '/users/yanliyuan/library/dev eloper/coresimulator/devices/dfa41111-c50f-4c9b-8d01-dad0f38bc6b9/data/containers/bundle/application/ 9a82a689-5b32-4828-b54a-55112eb8be17/easyq.app/googlemaps.bundle/gmscachestorage.momd/storage.omo '
2015-10-24 22:56:31.805 easyq[2510:176045] coredata:failed to load optimized model at path '/users/yanliyuan/library/dev eloper/coresimulator/devices/dfa41111-c50f-4c9b-8d01-dad0f38bc6b9/data/containers/bundle/application/ 9a82a689-5b32-4828-b54a-55112eb8be17/easyq.app/googlemaps.bundle/gmscachestorage.momd/storage.omo '
2015-10-24 22:56:31.816 easyq[2510:176045] coredata:failed to load optimized model at path '/users/yanliyuan/library/dev eloper/coresimulator/devices/dfa41111-c50f-4c9b-8d01-dad0f38bc6b9/data/containers/bundle/application/ 9a82a689-5b32-4828-b54a-55112eb8be17/easyq.app/googlemaps.bundle/gmscachestorage.momd/storage.omo '
2015-10-24 22:56:31.842 easyq[2510:176045]-[gmsmapview animatetocameraposition:]: Unrecognized selector sent to Instance 0x7fd3727282f0
2015-10-24 22:56:31.875 easyq[2510:176045] * * * terminating app due to uncaught exception ' Nsinvalidargumentexception ', re Ason: '-[gmsmapview animatetocameraposition:]: Unrecognized selector sent to instance 0x7fd3727282f0 '
IOS App integrate Google Map problems and Method to solve them