Apple Announces Improvements to Battery Life and Storage Space Usage in iOS 9 and More 

  
iOS 9 not only comes with a slew of new features, but the software update will bring a variety of performance improvements for the operating system, making it better on older devices and newer devices alike.
  
Apple announced improvements to battery life in iOS 9, such as adding an extra hour of battery life to existing devices without changing anything about the user’s device or applications they use. Moreover, a new switch can put the iPhone into low power mode that can add an additional three hours of battery life in a pinch where you need to preserve your dying device for emergencies.
In addition to improving battery life, Apple also says that storage management is made better in iOS 9. Developers creating applications for iOS 9 will notice that Xcode improves the storage usage of applications they make. For OTA (over the air) updating, iOS updates will now take far less storage to update to. Apple notes less than 2GB of usage for updating to iOS 9 despite the operating system having a file size of over 4GB on some devices.
iOS 9 will be available as a developer beta today, and will be available to the public in the Fall as a free upgrade.