Since the first iOS 6 beta, the iPhone 4 and iPhone 3GS were supported. Of course, there are features like maps navigation and view in 3D that Apple has not enabled for these devices.
Although Apple’s maps are not the best, which is perfectly reasonable, you might want to try these features on your devices. All you will need is a Jailbroken device running iOS 6 with installed Cydia.
- Launch Cydia
- Click the Search tab at the bottom right
- Search for “Unlock iOS6 Maps” and select it from the results
- Press the Install button at the top upper right of the screen
- Then click the Confirm button
- Since it has been successfully installed, click Restart SpringBoard
Voila!!!. When you restart SpringBoard you should have the turn0by-turn voice navigation and 3D maps on your iPhone 4 or iPhone 3GS devices.