Step 2: Next, select a film or show that you want to download, and open the video details. Once installed, launch the app and sign in to your Amazon Prime account. The look and functionality are surprisingly consistent across them all. You can also get the app for Mac and Windows desktop computers. Also, you’ll need the Amazon Prime Video app, meaning you’ll need a compatible Fire, Android, or iOS device. Step 1: First of all, you’ll need an Amazon account with a subscription to Amazon Prime. Compatible Amazon, Android, iOS, or desktop device