If you've ever used the Amazon Prime Video app on a Google Play Android device in the US, you've probably had to do some work to get it installed. Your options were pretty much to either side-load the app directly, or side-load the Amazon Appstore and install it through there. Either way, at some point you had to turn on the option to allow apps from unknown sources, and frankly, that's not safe.
The app's been available in the Play Store for some time in over 200 regions, but not in the United States for whatever reason.
Luckily, the app is finally available through the Google Play Store in the US, so installing it will be as simple as installing anything else. While the app is named after Amazon's Prime Video service, it's not limited to movies and TV shows that are available through Prime. As with the iOS version, you can watch shows that you've purchased, but unlike on iOS, you can actually purchase additional content through the app.
If you want to try out Amazon Prime Video for Android, you can download it from the Play Store here.