It looks like Google's feud with Amazon won't end anytime soon. A war has been brewing ever since Amazon pulled Chromecast, Apple TV, and other competing devices from their store in 2015, but the latest exchange is a huge blow to people using Amazon Fire tablets and streaming TV sticks.
The XDA Portal team reported that Google is now blocking the installation of Gapps (Google's own first-party Android apps) on uncertified devices. Android devices that have passed Google's compatibility and certification tests will see no change, but other devices that run unofficial forked versions of Android will greatly suffer.
Chief among these types of uncertified devices are Amazon's Fire OS models — Fire TV, Kindle Fire tablets, and other products with the Fire branding. These devices all run a forked version of Google's Android and have benefited greatly by having easy access to Google's library of Android apps. This will no longer be the case.
Without the ability to install Google apps, Fire OS users will no longer be able to access the Google Play Store, which is the world's largest app store.
Previously, getting the Google Play Store on a Fire device was simple — just sideload the app and pretend you have a certified Android device. The base OS is the same as Google's version of Android, so Amazon customers with a little wherewithal could then use official Android apps on the unofficial Android port that is Fire OS. That ends now.
If the device's operating system has a build date of March 16, 2018 or newer, Google apps will now start checking to see if the device is certified. This process relies on Android's SafetyNet system, which is not present on Fire OS devices. Therefore, as soon as your Fire OS device gets an update from here on out, Google Apps, including the Play Store, will stop working.
Third-party apps you've previously installed on your Fire OS device through the Google Play Store will continue to work, but the store itself should cease working. The only real way around this issue would be to root your Fire OS device and use something like Magisk to trick Google apps into thinking the device is certified.
A more palatable alternative may be to sideload the Yalp Store, which at the time of this writing, still allows you to download and install apps from the Google Play Store on an uncertified device. The interface isn't as pretty, but it gets the job done. You can read more about that process below.