Here is my experience so far...
If you use a service like SmartDNS or Unblock-US, you can watch Netflix from anywhere in the world using your UK Netflix account. No need for VPNs. The services costs an extra $5 a month but worth it. Works great on all devices, including my Fire TV.
The service also works a treat for Hulu, but the Fire TV app is for Hulu. This needs a US credit card to subscribe.
For Amazon Instant Video (the pay to rent/buy service), you need a US Amazon.com account and a US credit card. You can use a service like US Unlocked (not to be confused with Unblock-US mentioned above
) which lets you register for a virtual US credit card with a US billing address and works great on Amazon and Vudu. Been using it a few years, but it does require a huge leap of faith to sign up for it - you need to send bank details etc for initial setup. I haven't had any issues so far, but appreciate many won't want to do this.
You can probably also get Amazon.com vouchers but have not tried this for Instant Video . Lots of sites sell them
The kick in the teeth for me is Amazon Prime and not having access to the UK service. On the Fire TV it's not an app that you launch so to speak, it's integrated into the menus. Everything that is served is the US content. Unlike Netflix, which uses the same app to server different content based on your region, Amazon has different apps for each region.
So to get UK Prime content, we need a UK version of the app sideloaded. At least that's my conclusion. The best version would be the Google TV apk (
https://play.google.com/store/apps/details?id=com.amazon.avod) and there are some discussion around about ripping it, but I don't think anyone succeeded. We would also need it to be the UK version of the app.
As an example, on PS3, to get UK Prime, I need the app from the US PSN store, and for US Prime you need the one from the US PSN store.
The other challenge is sideloading it. I tried sideloading this
Amazon Instant APK just as a test, and I got an error saying com.amazon.avod already installed, which is the main Prime app on the Fire TV. Someone much smarter than me would need to figure out how to change the name of the app/package so it can be installed alongside each other. Even if you could, this app won't work anyway to get UK content (or even work at all with a remote), but it's one step closer if we can get two versions of the Amazon app installed side by side.
Hope that helps someone somewhere
It's still a great piece of kit - only thing I'm missing is UK Prime.
Cheers