jarledb: If you get "unavailable" in the price box when trying to install an app, then the Amazon account you are using is set to the wrong country. Finally figured it out just a day or so ago.
Its possible to log into Amazon and change the country of the device.
You do this in Your Account -> Manage Your Content And Devices
Left menu: Country settings
Mine was set to Norway and that did not allow me access to the apps like Youtube etc. Setting it to US was easy enough. My Fire TV has still to discover that its allowed to download content though, but I can add apps via http://www.amazon.com/b?node=7031433011
Not sure wether I need to reset the box to get it to understand its allowed to download now. Will see if some setting time out on it and use the web interface to add apps until I get fed up enough. :D
So should I set the country code to USA or to New Zealand?

