Go to cydia ( first jailbreak it if you haven't) then install whatspad. After that install from cydia vshare (alternative to installous, cause its been shut down). Download whatapp from their, then launch it. It will ask you to enter your phone number, when you do it, it will send you a message with a code, activate it with that code, and your done.
Khaled wrote Cannot give you for sure if these still work today, but just saying that it used to work in the past.
Yes, it is still working.
