To redeem coins offered by Amazon.com, you must use a mobile device to access the Amazon Coins page at the company's app store, select an app to purchase, select coins and then click the Get App button. The purchase summary page displays the subtotal, tax and total number of coins used to make the purchase.
The Amazon Coins program is designed to work cohesively with Android mobile devices and Amazon Fire devices. By making gentle taps on your device's screen, you can purchase apps or make in-app purchases using coins from your Amazon Coins account. If you don't wish to use coins to buy an item, you can choose the regular one-click option and pay using another funding source. Items you buy with Amazon Coins may be taxed using the coins, and Amazon automatically calculates the number of tax coins required for each purchase.
If you attempt to make a purchase with coins but don't have enough coins in your account to cover the cost, you'll see that Amazon Coins is greyed out. To see how many coins you have, log in to your Amazon account and visit the details page of any Appstore item that sells apps for money, then look under the Spend Amazon Coins heading. Most apps in the Appstore can be purchased with coins, but there are a few exceptions.