At WWDC 2013 Apple announced iOS 7 and just after that iOS 7 beat 1 build 11A4372q is released to registered Apple developers which is available for download via iOS Dev Center which is compatible for iPhone, iPod Touch and iPad.
The latest Apple’s mobile iOS, iOS 7 integrates with new features and an amazing new interface, that make it a big update to iOS after its first release in 2007.
The iOS 7 is compatible with iPhone 4, iPhone 4S, iPhone 5, iPod Touch 5, iPad 2, iPad 3, iPad 4 and iPad Mini whereas Apple dropped support for iPhone 3GS and iPod Touch 4G in iOS 7.
Right now iOS 7 beta 1 is available for iPhone and iPod Touch and it will soon reach to iPad as well.
Download iOS 7 Beta 1
See also:
Apple Announced iOS 7 at WWDC 2013
iOS 7 New Features