His trick is similar to the hack which let me install Gmail, Google Reader, and other Google apps on the Kindle Fire HD last year. He's gotten Gmail, Google Play Books, Chrome, and Google Search working on the Fire HDX, but at this point Google Play Store and Google+ still don't work.
Here's how you do it.
First, you’ll need a file manager or some other way to access the install files on your Kindle Fire HDX.
Amazon won’t let you do this via their setup, unfortunately, so I recommend that you head over to this post and install the 5 apps I suggested for the Kindle Fire HD. Or you could skip that and install ES File Explorer, an app which you can find in the Amazon Appstore on your Fire HDX.
- Download the following files and transfer to your Kindle via USB connection to your PC. I suggest that you copy them to the “download” folder of the Kindle Fire HDX; it will be the easiest to find again.
- Open the ES File explorer app and then open the download folder. Select and install Google Account Manager.
- If you are prompted by a warning that app installs are blocked, follow the prompts to go to the settings menu and change the appropriate setting. Then go back to ES File explorer and try to install Google Account Manager again.
- Reboot your Kindle Fire HDX by pressing and holding the power button and then selecting the shutdown option. Then restart it.
- Install Google Services Framework.
- Install Google Play Services.
- Install Gmail.
At this point you should be able to open the Gmail app and log in to your account. You can ignore any warning messages.
Once you've logged into your Gmail account you can then download and install other Google apps. If you need help finding the apps, check out the 1Mobile app store. That is one of the better sources of free apps, including reading apps, utilities, and even Google apps.
Last year I reported on a similar trick which let me add Google apps to the Kindle Fire HD, but unfortunately it turned out to be less useful than I had hoped. The Kindle Fire HD (2012) didn't support notifications and running Google apps in the background, and as a result some apps (Gmail, for example) would only check for new content when they were open.
I am concerned that the HDX might have the same issue. I'd love to hear back from anyone who tries this. How well did it work?