This video shows a little work around on how to watch HBO Go on a rooted kindle fire.
Rooting your device could cause damage if you are not sure what you are doing. I am not responsible for any damage caused to your devices if this occurs.
These videos are prerequisites you need in order to watch HBO Go on your Kindle Fire.
How to root the kindle fire:
How to install Android Market Place:
Additionally: The User Interface I am running on my Kindle is the Go Launcher EX which can be found on the Android Market Place.
The Background is a custom background from Go Launcher.
To disable the Kindle background and enable your own can be found here:
Hope you enjoy.