Since the Amazon Fire TV is a device that runs Android, you can install any Android app onto your Fire TV, but to varying degrees of success.
To get apps onto your FireTV, you can do it the manual way or the easy way.
Manual: Download an APK from an APK websites (e.g. APKPure or APK4Fun)*. Copy onto an SD card and insert the SD card into your Fire TV.
Easy Way: Follow the steps in this Make Use Of article. In short, you use the apps already downloaded on your phone and it will copy and install the apps onto your Fire TV.
You will probably hit problems with your downloads though, since they were not designed for the Fire TV.
- If an app requires Google Play Services, it will not open. You will need to try installing Google Play onto your Fire TV.
- If an app is not designed to play on a TV, the app will be stretched and unclear.
- * These APK websites can provide compromised versions of apps, do use at your own risk.