Tumblr has launched a new iPhone/iPad app for creating and sharing photosets. It's called, fittingly, Photoset. "Photosets have been one of our favorite additions to Tumblr," the company says 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." "The new Photoset app is an elegant way to create photosets, even if you’re not using Tumblr," the company adds.