Follow the below steps to install iOS 9 without Tool and Developer Account
Step 1. Download all necessary files.
Step 2. Connect your device and open iTunes.
Step 3. Hold “Option” on a Mac or “Windows” Key on a Windows PC and left click the “Check for Update” button in iTunes.
Step 4. Select your iOS 9 IPSW and select “Open”
Step 5. Allow 10-15 minutes for install. you are now enjoying the latest iOS 9 release on your device
Now Apple introduced the Rootless kernel-level security to prevent iOS 9 jailbreak. But Don't give us expectation to jailbreak your iOS 9 device, JB hackers have already presented new jailbreak concepts for iOS 9.
iH8sn0w,who developed the jailbreak tools like Sn0wbreeze demonstrated the video for jailbreking the latest iOS 9. iH8sn0w demonstrated the untethered jailbreak for the yet-unreleased iOS 9 on youtube within 24 hous of its launch
iH8sn0w has jailbroken his iPhone 5 running the iOS 9 shown in the video below:
However,iH8sn0w does not yet officialy released the tool used for jailbreak.