What can i do to not lose my game account?

So i have an iPod and I'm getting an iPhone soon. And when i get the iPhone i will lose a lot of games. The game that i really don't want to lose my progress in is "restaurant story".is there anything i can do so that i would have the same game acoount on my iPhone? ( the IOS version of my iPod is 5.1.1 )

Don't give your ipod keep both and play you game simple