How to download iOS 9 on your iPhone and iPad right now
The software launched on September 16, giving everyone access to the iPhone and iPad update. iOS 9.1 public beta came out just before this. But company's instructions aren't very comprehensive.
It did take a few attempts to install iOS 9 due to everyone taxing Apple's servers all at once, but the new features outweigh those temporary problems and minor beta bugs of being an early adopter.