Although older Fire tablets don’t have external storage, newer Fire tablets provide external storage options through memory card slots. The settings in your Android Manifest file determine where your app is installed on Fire devices, either on external storage (such as an SD card) or internal storage (using the device’s memory). Generally, your app should specify external storage as the default install location, because filling up internal storage can lead to fewer app installs, poor app ratings, and a negative customer experience.
For information about how to specify this in your app manifest, please see our documentation: