When I run the demo project, Execution completed but there is error saying: 2014-02-27 16:50:32.330 THSpringyCollectionView[1073:60b] Unknown class cellIdentifier in Interface Builder file. 
When I run the demo project, Execution completed but there is error saying:
2014-02-27 16:50:32.330 THSpringyCollectionView[1073:60b] Unknown class cellIdentifier in Interface Builder file.