I’ve mentioned a number of resources related to custom UICollectionView layouts such as this tutorial on making great looking custom UICollectionView layouts and most recently a flow layout that provides a grid view supporting swipe to select and deselect gestures.
Here’s a custom UICollectionViewFlowLayout that uses hexagonal cells submitted by Cyril Chandelier called CCHexagonFlowLayout.
With CCHexagonFlowLayout you can easily customize the orientation, size and spacing, and add in supplementary views.
Here’s a set of images from the readme showing CCHexagonFlowLayout in portrait and landscape:
You can find CCHexagonFlowLayout on Github here.
A nice hexagon UICollectionViewFlowLayout.