Let’s not belittle the Amazon ecosystem citing the lack of the Google Play Store as a pretext. The Fire OS, or as we call it, is still essentially Android. This means, despite not accommodating the famed Google Play Store, out of the box, Fire Tablets allow you to play around with the platform and install the same in due course.
Essentially a 10-minute long process, regardless of the method you choose, installing the Google Play store on the Fire Tablet opens a whole new world of possibilities for you. But then, why would you even need the Play Store when you already have the Amazon-powered app store at your disposal?
As far as an out-of-the-box offering is concerned, the Amazon App Store feels a bit like the Apple-backed app store, with an improved keyword searching mechanism as compared to the Play Store. But then, the Google Play Store simply blows away the app store, in terms of the sheer diversity of selections, especially when the likes of Google Maps, Chrome Browser, Gmail, and other apps are concerned.
Therefore, even though the Amazon App store proffers quite a decent collection of Android-specific applications, premium resources, and the concept of redeemable Amazon coins, having the Google Play Store is still desirable as you would then be able to make the most of the Fire Tablet and its potential as a Kindle, comic creator, streaming device, and whatnot.
How To Install Google Play on the Amazon Fire Tablet? 
Firstly, you need not root and violate the warranty of the concerned Fire Tablet to install the Google Play Store on it. While the most rudimentary process involves installing a few APKs on the tablet by first allowing app installation from Unknown Sources, you can even explore the Android Debug Bridge or the ADB pathway to make app installations easier and more comprehensive.
Not just that, regardless of the Play Store installation method you follow, the SD card, if any, needs to be removed. As the APKs automatically identify the external storage and get downloaded there, installing and accessing them might become difficult in time.
Also, the ADB method makes the tablet function like a fully-equipped android smartphone, thereby cutting out the issues pertaining to hidden applications and the extensive usage of third-party resources like the APK Mirror.
Method 1: Via APK Files
In case you are at ease with the APK files, this method seems more plausible. However, the same can be segregated into four broader sections i.e. preparing the device, downloading relevant files, installing the APKs, and eventually running the Play Store for the first time.
1. Preparing the Tablet
Step 1: Head over to the Settings tab, accessible over the Notifications Bar. Once open, click on the Device Options.
Step 2: Consider updating the Fire Tablet as it would help you choose the most relevant APK versions, depending on the Fire OS model you are running.
Step 3: Provided you have updated the Tablet OS by now, identify the ‘Device Model’.
Step 4: Retract to the Main Menu and select ‘Security and Privacy’ from the set of options. Once open, allow app installation from unknown sources, and click ‘OK’ to update the existing settings.
2. File Downloads
Step 1: Now that you are already aware of the Fire OS version that the concerned model is running, it’s time to select the files accordingly.
Note: As a matter of fact, you need to download four altering APKs to get the installation started. These would include the ‘Account Manager’, ‘Services Framework’, ‘Play Services’, and the ‘Play Store’, in the same order as mentioned.
Step 2: As mentioned, download the Google ‘Account Manager’ depending on the tablet of choice:
Step 3: Next, you need to select the Services Framework link of choice from the table and download the same for subsequent usage.
Step 4: Download the relevant version of the Google ‘Play Services’ from the table and prepare the tablet further.
Step 5: Finally download the source APK of the ‘Play Store’ right at the end. Also, ensure that the files are only downloaded and not installed. For the final APK, ensure that you get hold of the latest one.
3. Install the APKs, Discreetly
Step 1: Locate the place where the apps have been downloaded. Most probably, you would find them in the Files app of the tablet, leading into the ‘Downloads’ subfolder.
Step 2: You will find all the APKs downloaded here or else you can search them manually by feeding in the names.
Step 3: Install all the APKs one by one and Reboot the tablet
Run the apps for installation in the exact order they have been downloaded, starting Accounts Manager. Once you click on the file, simply read the instructions on the screen and hit install.
The Google Services Framework needs to be installed next followed by ‘Play Services’. However, as the Play Services framework is integral to the Play Store installation, it might take some time.
Finally, select the right APK file from the list and install the Play Store, as you have already mounted the rest of the three APKs.
Once the applications are installed in the given order, reboot the Fire tablet.
4. Sign-in to your On-Device Play Store
Step 1: Once the tablet switches on, you will find the newly installed Play Store app on the home screen.
Step 2: Sign in using the Google credentials and follow where the prompts lead.
Note: By this time, you should have a fully functional play store by your side, with a few apps hidden as Fire Tablets aren’t certified as per the Safety-NET credentials.
Method 2: Via Android Debugger
This process involves installing the Play Store using a personal computer. As it requires you to connect the tablet with a PC, you would require a USB cable for the same. Also, this method helps you bypass the restrictions, pertaining to the hidden apps, an issue often encountered whilst following the first method.
Step 1: To follow this method to the letter, you must first open the Settings tab on the tablet head over to the device options.
Step 2: Enable Developer Options
Once there, you need to reach for the serial number and hit it at least 7 times, repeatedly to activate the Developer Options for the given tablet and serial number. As Fire OS is still a modified version of the Android operating platform, it would still allow you to access the developer options with ease.
Step 3: Subsequently, click and enable the ADB access and agree to the warning if it shows up.
Note: By this point, you should be able to use the USB cable to connect the concerned Fire Tablet to the PC. In case downloading drivers is an issue, you can always download them online and place them on the laptop, to ensure that the machine readily detects the tablet.
Once the tablet is detected, unlock the same and activate the USB debugging feature.
Step 4: Provided the PC is ready, download the required package by clicking on the script link.
Note: The script link leads to a zip file, which downloads directly onto the PC. You need to extract the script and ensure that it is located easily, preferably in the File.Bat format.
Step 5: Install Google Play
Click on the .BAT file to run the script in the Command Prompt format. Once the command prompt tab is active, Type 2 and press Enter. This would install the Google Play store on the Tablet.
Once the process is complete, reboot the tablet. You can now see the Play Store app icon on the home screen with apps ready to be downloaded.
Installing the Google Play Store on the Amazon-backed Fire Tablet is smooth sailing to be precise. However, as the process is more of a workaround, you might troubleshoot the same occasionally to ensure a more refined experience.
This would mean clearing app data frequently, rebooting the tablet upon installing any app from the Play Store, and even Resetting the tablet once before installing the Play Store, using any of the mentioned methods.
While these strategies might feel overwhelming to you, it is good to follow the same to speed up the Fire Tablets further, as these Amazon-powered tablets aren’t exactly known for the processing speeds.