Ahead of tomorrow’s iPhone 6s and iPhone 6s Plus launch, Apple has released iOS 9.0.1 for download. This means once you purchase your device tomorrow, you can update to iOS 9.0.1 to get the latest bug fixes and improvements.
You can find standalone downloads for the firmware below via @iOSReleases:
— Firmware Releases (@iOSReleases) September 24, 2015
Just yesterday, iOS 9.0.1 was released for iPhone, iPad and iPod touch. Your iPhone 6s is coming soon, folks!