KTCenterFlowLayout is a subclass of UICollectionViewFlowLayout which Aligns cells to the center of a collection view. It effectively enforces the minimumInteritemSpacing.

# In your Podfile

pod 'KTCenterFlowLayout'

Objective-C:

KTCenterFlowLayout *layout = [KTCenterFlowLayout new];
layout.minimumInteritemSpacing = 10.f;
layout.minimumLineSpacing = 10.f;

[[UICollectionViewController alloc] initWithCollectionViewLayout:layout];

Swift:

let layout = KTCenterFlowLayout()
layout.minimumInteritemSpacing = 10.0
layout.minimumLineSpacing = 10.0

UICollectionViewController(collectionViewLayout: layout)

See the layout in use in the ./Example app:

This layout doesn't work with UICollectionViewScrollDirection.horizontal.

This layout doesn't work with self-sizing collection view cells (estimatedItemSize). Of course, neither does the vanilla UICollectionViewFlowLayout. Pull requests appreciated from anybody interested in solving self-sizing layouts!