If you are iPhone Jailbreak user, GreenPois0n (iDevice Exploit Injector) is the name must be remembered. Many iPhone, iPad, iPod Touch user using Jailbreak code from chronic dev team. Check out Twitter status from chpwn. So, If you feel like you can make GreenPois0n better, faster, prettier, well, now you can join on this project.
You can download GreenPois0n source code from github and start working on it.