Iphone 4 Jailbreak Ios 4.2.1 And Iphone 4 Unlock Solution With No Technical Knowledge

http://ejournal.upi.edu/index.php/WapFi/user/viewPublicProfile/121097

The books can be read on any ios 12 jailbreak but will require iBooks to be installed on the device. Since that's a bit more involved (and device specific) we'll leave you to Google search for answers on that.