Apple just announced on their event earlier today that the iOS7 will be available to iPhones and iPads starting September 18. The new OS version will be compatible starting with iPhone 4 and later, iPad 2 and above, iPad Mini and iPod touch 5th Generation.
The iOS7 debuted last June is the first major UI overhaul for the Apple OS. It features all new icons, folders, dynamic wallpapers (ala live wall paper in Android), control and notification center with toggles (similar to Android notifications), AirDrop for file sharing and bunch more.
The new OS is still dependent with iTunes in uploading files and multimedia, there is still NO proper file manager, limited codec support and of course it is still a closed system.