iOS 7 will be compatible with

                                                      iOS 7 The mobile os from all new perspective :-APPLE   iOS 7 the new version of mobile os from APPLE  introduces great new features like Control Center, AirDrop for iOS, and smarter multitasking. It also makes the things you do every day even easier, faster, and more enjoyable. 

will be compatible with:

iPhone 4

iPhone 4S

iPhone 5

iPod touch 16GB

iPod touch 32GB/64GB

iPad 2

iPad with Retina display

iPad mini