From the screenshots, you can see the photo viewer displaying a scrubber view (row of thumbnails). This strongly suggests that this app is built using Jeff Verkoeyen's Nimbus framework. If you're building (or built) apps using Three20, it'll probably be good idea to follow the Nimbus framework on Github.
http://techcrunch.com/2011/07/25/facebook-ipad-app-pictures/...
http://jverkoey.github.com/nimbus/interface_n_i_photo_scrubb...