To rename the icons on your iPhone, iPad, or iPod touch directly from the springboard, you will first need a jailbroken idevice. Once your device is jailbroken you can launch the Cydia app store and grab a new tweak known as Icon Renamer from the BigBoss repo.
Once installed, there are no new icons added to your springboard. To utilize the tweak, tap and hold an icon to enter into “jiggle” mode (the same way you would normally delete or rearrange an app). You will now be able to tap an icon to rename as shown in the image above. That’s it. Enjoy.