Change your Android app installation settings
On the home screen, swipe down from the top of the screen.
Settings > App Manager > Installing Apps.
Do any of the following:
• To allow the installation of Android apps from sources other than the Amazon Appstore, turn on the Allow Apps
from Other Sources to be Installed switch.
• To inspect Android apps and identify apps that are potentially harmful to your device or data, turn on the Inspect
Apps Before Installing switch.