Top Regions
1.Display the most popular regions in which photos have been taken on flickr.
2.The popularity of a region is determined by how many different photographers have taken a photo in that region among the photos you’ve downloaded from Flickr. Only show the 50 most popular regions in your UI.
3.When a region is chosen, all the photos in your database that were taken in that region should be displayed (no sections are required). When a photo is then chosen,  show it inside a scrolling view that allows the user to pan and zoom (a reasonable amount).Whenever a photo’s image appears on screen, it should automatically zoom to show as much of the photo as possible with no extra, unused space. Once the user zooms in or out on a photo by pinching, though, you can stop auto-zooming that image.
4.Your application’s main thread should never be blocked (e.g. Flickr fetches must happen in a different thread). If your application is waiting for something over the network, it should give feedback to the user that that is happening.
5.Your application must work in both portrait and landscape orientations on both the iPhone and the iPad.