500px for iOS lets you browse and explore all kinds of photos from all over the world right on your iPhone and iPad. Version 2.2 has added some improvements that let the interface itself get out of the way more so you can focus on the photos themselves, including an edge to edge design.
With a new translucent, edge to edge design, photos come stand out much more than they did before. Gestures have also been added to the comment system. Swipe comments to like or promote them. The iPad version of 500px has received some new features as well including better avatar support in the flow view as well as a better photo details drawer.
I'm not sure I'd necessarily call this update an iOS 7 ready one though as the keyboards have yet to be changed and they stand out like a sore thumb. Other than that, it's a decent update. Unfortunately, you still can't upload your own photos from the app, you'll still need a web browser to do that for now.