Navigate down and select the box, then type in “ Downloader” to search for the app. A search box appears below the “Find” option.From the “ Home” screen, click on the “magnifying glass” (the “Find” option) in the top-left section.Therefore, the Downloader app should get installed first. Turning on the “Install apps from unknown sources” setting requires you to select the app that can install other applications, which is the Downloader app. This is the first requirement (installing Downloader and not activating developer options yet). Downloader is the most common choice because it is readily available on the Amazon Appstore, and it includes a built-in installer/file browser. To download Android apps using Aptoid as an alternative to the Play Store, you need an app that downloads other apps. Install Downloader on Your Fire TV, Fire TV Stick or Fire TV Cube Here’s how to install the Google Play alternative known as Aptoide on an Amazon Fire Stick. However, even the Play Store is not 100% safe these days. Be warned, installing Aptoide on your Amazon Fire TV Stick does pose security risks since you allow third-party installations.