Apple yesterday released its first update for iOS 9. If you have yet to take the plunge to iOS 9, then your iPhone may still offer the outdated iOS 9 update on the Software Update screen instead of version 9.0.1 that addresses a number of bugs. Happily, there is a way to skip the iOS 9 update and go from iOS 8 straight to iOS 9.0.1.
First, open Settings > General > Usage > Manage Storage.
Next, find iOS 9 listed in the list of apps on the Storage screen and tap it. Then tap Delete Update.
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Screenshot by Matt Elliott/CNET
After deleting the update, you will need to disconnect from your network and then reconnect. The easiest way to do this is to swipe up from the bottom of the screen to call up the Control Center panel and turn on Airplane mode for a few seconds and then turn it back off to reconnect.
You will also need to close the Settings app. Double-click the Home button and swipe up on the Settings app to close it.
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Screenshot by Matt Elliott/CNET
Now, open Settings again and go to General > Software Update, where you should see iOS 9.0.1 offered instead of iOS 9.
(Via OS X Daily)