It's often that we see iOS and Android concepts on sites like Behance, Dribbble and DeviantArt. Weather iOS 7 is a cool, minimalistic and flat concept for iPhone. The concept is currently work in progress but it still looks well enough to be crafted into a real iPhone app.
We have seen a lot of concepts before for the iOS 7 flat icons, iOS 7 app redesign concepts and iOS 7 A8 concept which was inspired by Alexey Masalov's original concept. The designer of the concept, Harvey Lorimer has titled the project on Behance "Weather for iOS7 (Big Project, stay tuned!)", so we can expect this concept into a real app soon.