How to install IOS 7 :
(Update !! 18-09-2013) Finally Apple has released io7 Final Version.
if got errors while trying download iOS 7 over-the-air try this solution.
How to Download IOS 7 ? IOS7 Beta by Apple is only available for developers, but we put links that everyone can download, We have made io7 download available for iPhone 5 and iphone 4 gsm rev a , also you can download io7 by apple developer account, Apple released firmware for ios 7 download for iphone 4 gsm (4) ,IOS7 got major change in system interface and even more of the characteristics and services, io7 free download from below links, Enjoy:
(Update!) Apple released ios7 beta 3