IOS 9

iOS 9 is the ninth major release of the iOS mobile operating system designed by Apple Inc., serving as the successor to iOS 8 and predecceesor to iOS 10. It was announced at the company's Worldwide Developers Conference 2015 alongside tvOS 9, watchOS 2 and OS X El Capitan on June 8, 2015, and was released on September 16, 2015. iOS 9 focuses less on new features and more on under-the-hood optimizations, as well as battery improvements. iOS 9 only requires over 1 GB or iPhone or iPad space to download.

History
OS 9 debuted at Apple's Worldwide Developers Conference on June 8, 2015, with iOS 9.0 beta 1 being made available to registered developers straight after the keynote, and a public beta made available to members of Apple's Beta Software Program in July. iOS 9 was released publicly on September 16, 2015.

iPhone

 * iPhone 4S
 * iPhone 5
 * iPhone 5C
 * iPhone 5S
 * iPhone 6
 * iPhone 6 Plus
 * iPhone 6s
 * iPhone 6s Plus

iPad

 * iPad 2
 * iPad_(3rd_Generation)
 * iPad_(4th_generation)
 * iPad Air,
 * iPad Air 2
 * iPad Pro

iPad Mini

 * iPad Mini
 * iPad Mini 2
 * iPad Mini 3
 * iPad Mini 4

iPod

 * iPod Touch (5th generation)
 * iPod Touch (6th generation)
 * NOTE: The IPhone 2g and 3G And 3GS And 4 Are Not Supported And The IPhone 4S Is No Longer Making Updates Anymore And Its With The Support.

Trivia

 * This is the last iOS to feature Slide To Unlock.
 * This is the first iOS to use a new flat Music icon.
 * This is the first iOS to feature a new flat switcher.
 * This is the first iOS to feature News Becuase The Newsstand Name Has Removed And News Is Now A name and not stand at the end of the name.
 * The Original Flat Music Icon Was Going To Be In IOS 9 Beta Only.