I’ve mentioned a number of excellent calendar components most recently this excellent sideways scrolling day picker, and pointed out some great UICollectionView examples the most popular being this example showing how to create a Pinterest style grid view with UICollectionView.
Here’s a good looking calendar component from Evadne Wu called DayFlow that utilizes UICollectionView.
DayFlow provides a good looking monthly calendar within an infinite scrolling setup making it ideal for quickly scrolling through the dates on the iPhone.
Here’s a video demonstrating DayFlow in action:
A nice calendar component, and UICollectionView usage example.