Apple is not relying any more on Google Maps so that the company has introduced its own Maps app in iOS 6. Now, if you want to enable 3D Maps on your iPhone 4, iPhone 3GS or iPod Touch 4G then continue reading after the break, as officially it does not support older iDevices.
How to Enable 3D Maps on iPhone 4, 3GS or iPod Touch 4G
On your jailbroken iDevice navigate to Cydia and install iFile
Download and install the 3D Enabler package
Kill Maps app on your iDevice and again open it. You will find 3D Maps icon on Spring borad