Firestick and Showbox are not compatible. Showbox is a great app, but it's not available on the Amazon Fire Stick platform. If you want to watch movies and TV shows with Showbox, you'll need to use another device such as a smartphone or tablet. TIP: If you're watching movies in HD on the Fire Stick, download and install the Kodi app to your Amazon device. The Kodi app will allow you to watch movies in HD quality on your Fire Stick.