“Photosets have been one of our favorite additions to Tumblr,” explained the Tumblr team in a blog post. “You’ve surprised us a thousand times over with your creativity. It’s hard to imagine Tumblr without photos, and we love the power a set of photos has to tell a story.”
To create a set, you can drop and drag photos from your iPhone or iPad, rearrange them on the screen, and add a caption.
Although the app is separate from Tumblr, the photosets can be shared on the blogging site, as well as Twitter, email, and other networks via a unique URL.