Sund0wn

Sund0wn is a downgrade utility which allows tether and untether downgrades for iOS 6.0-7.1.2 for the iPhone 4. It is for the Windows only written by iSuns9. It works on all iPhone 4 models. This is useful if you want to use older iOS versions. Even if Apple doesn't sign that firmware anymore, sund0wn creates a restoreable IPSW so that you can install the firmware and tether boot after.

Credits

 * iSuns9 - author
 * geohot - limera1n Exploit