Instagram has released an update that corresponds with iOS 7 and includes size increases when displaying photos and videos. Now, photos and videos will take up the full width of your screen when viewing them in your feed. The photos are also larger in grid view. Additionally, profile pictures are now circular instead of square.
The update also cleans up the look and feel of the overall Instagram interface so that it melds better with iOS 7.
Instagram 4.2 is now available for free here in the iTunes App Store.