CatCollectionViewReorder is wirtten with IOS 9 new methods,it is easy to make your UICollectionView reorderable
#import "CatCollectionViewReorder.h"
CatCollectionViewReorder *collectionViewReorder = [[CatCollectionViewReorder alloc] init];
[collectionViewReorder bindToCollectionView:_collectionView];
//Make sure rewirte this delegate method
- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath {
return YES;
}