Install Cydia after GreenPois0n Jailbreak 4.2.1
Once you have successfully Jailbroken your iDevice 4.2.1 with the help of Greenpois0n tool. You have to follow a simple tip in order to install cydia in your iDevice. Follow the tutorial below to install Cydia after GreenPois0n Jailbreak 4.2.1: Step 1: In your iPhone, iPad, or iPod Springboard your will see a new icon, named as Loader . Open it. Step 2: Then in Loader app, click on Cydia and press install Cydia tab. Step 3: It will automatically download and install Cydia in your iPhone, iPad, or iPod Springboard. Thats all. Just above you have learned how to install Cydia after GreenPois0n Jailbreak 4.2.1, if your iDevice isnt jailBroken yet then you can use GreenPois0n tool to JailBreak it.