Instagram mirrors Pinterest with feature for organizing saved posts

Introducing New Ways to organize you’re Saved Posts. Instagram released a new feature called Collections, enabling users of the Facebook owned network to organize photos and videos they find into categories, much like Pinterest’s boards. You can find your collections on the saved posts tab on your profile. Just like all saved posts, your collections are private only you can see them.
http://blog.instagram.com/post/159679268807/170417-collections