CoolBooter is an all-in-one dual booting utility for jailbroken iOS devices, provided completely free of charge.

CoolBooter allows you to dual-boot another iOS with your current jailbroken iOS firmware.

CoolBooter modifies your device's partitions. This is dangerous, but required.
Please back your device up, and do not use a device that you would mind restoring to the latest available firmware.

CoolBooter currently supports going from any jailbroken iOS to an iOS firmware of your
choice on the iPhone 4, iPhone 4S, iPhone 5, iPhone 5c, iPad 2, iPad 3, iPad 4, iPad Mini 1G, and iPod Touch 5G.

CoolBooter is available by adding https://coolbooter.com to your sources in Cydia.

Follow @CoolBooter on Twitter for updates, and for support, just send a direct message.

CoolBooter is a utility created by Jonathan Seals, and was made possible by winocm, Rod Smith, danzatt,
xerub, iH8sn0w, axi0mX, and the iphone-dataprotection project.

CoolBooter Partitioner (gptfdisk fork) source
ios-kexec-utils source