Adjusting UICollectionView scroll speed/sensitivity

For anyone looking how to do it in Swift

 self.collectionView.decelerationRate = UIScrollViewDecelerationRateFast

Swift 5:

 self.collectionView.decelerationRate = UIScrollView.DecelerationRate.fast

UICollectionView is a subclass of UIScrollView, so you can adjust the decelerationRate in your collection view controller's viewDidLoad, like so:

Objective-C:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.collectionView.decelerationRate = UIScrollViewDecelerationRateFast;
};

Swift:

override func viewDidLoad() {
    super.viewDidLoad()

    self.collectionView.decelerationRate = UIScrollViewDecelerationRateFast
}