iOS 9.0.1 Downgrade Available
If you upgraded to iOS 9.0.2 and you don't like it, perhaps it is causing bad battery life or an app you rely on is not working right, you can downgrade.
Unfortunately, you cannot downgrade very far. Apple only supports an iOS 9.0.2 to iOS 9.0.1 downgrade at this time and it is unlikely that Apple will allow further downgrades.
If you upgraded away from iOS 8, you are now stuck on iOS 9.