Apple recently released iOS 9.0.1 few hours ago to bring several bug fixes and improvements.
This update contains bug fixes including:
● Fixes an issue where some users could not complete setup assistant after updating
● Fixes an issue where sometimes alarms and timers could fail to play
● Fixes an issue in Safari and Photos where pausing video could cause the paused frame to appear distorted
● Fixes an issue where some users with a custom APN setup via a profile would lose cellular data
To read more information about the security content of the update, please visit here: http://support.apple.com/kb/HT1222