You can use your credit to shop a huge selection of eligible apps and games, books, electronics, and more on Amazon.com and Amazon Appstore. Your earned credit will become available monthly, applied automatically to your next eligible purchase.
Use the link sent to your Android phone, then follow these steps:
Download Amazon Appstore
Use link sent to you in email to navigate to the Amazon Appstore download page
Tap on "Get Amazon Appstore" button
Enable Unknown Sources
In your phone Settings page, tap on "Security" or "Applications" (varies with device)
Enable "Unknown Sources" permission
Confirm with "OK"
Install and Launch Amazon Appstore
In your device's "Download" folder, find and tap on the "Amazon_app.apk" file