After rooting your android you can install unapproved (by Google) apps, update the OS, replace the firmware, overclock the processor, customize just about anything, and so on. So when you get a New Amazon Fire Phone, do you want to root the New Amazon Android Smartphone?

Video Guide to Root Amazon Fire Phone
Moreover you may need:
> Move Data from Old Phone to Fire Phone
> Transfer Data bewteen Computer & Fire Phone

> Back Up & Restore Everything on Fire Phone
> Recover Lost &Deleted Data from Fire Phone