Getting Started with Amazon Appstore SDK

Introduction

With the Appstore SDK, Amazon provides the following functionality:

DRM, or "license verification," is used to address 
developer concerns around unauthorized copying and distribution of apps. 
DRM is mostly used for paid apps. If your app has Amazon DRM applied to it, 
users must install the Amazon Appstore client (built-in to Fire devices) 
and they must be signed in to access your app. 
The DRM methods you integrate into your app checks 
with the Amazon Appstore device service to see whether the user has 
a valid license for your app. If the user does not sign in 
or does not have a valid license, the app does not run. 
However, any user can gain a license by purchasing the app through Amazon. 

With In-App Purchasing (IAP), users can purchase digital items within your app, 
such as extra lives for a game, in-app items for users to enhance their gaming experience 
(currency, extra moves, lives, bonus levels, mini-games, and so on). 
Or your app might offer a premium subscription with access to special content. 
IAP handles details about purchase flow, payment processing, app receipts, 
and rights management so that you do not have to code this purchasing infrastructure in your app.

A. Installation
Adding the Amazon Appstore SDK to your Android Studio project is now easier than ever. 
To add the Amazon Appstore SDK to your project, paste the following line 
into the dependencies {} object of your app’s build.gradle file.
(Note: this is not the same as the project’s build.gradle)

  implementation 'com.amazon.device:amazon-appstore-sdk:3.0.1'
 
 
B. Wild card versioning:
While this is not recommended for a live project due to unforeseen stability issues,
using wildcards in your version declaration can be useful in debugging or testing your app 
against the latest version of the Amazon Appstore SDK. Simply replace the version number 
with a + to use the latest iteration:

  // Pull and compile latest 3.x release of the Amazon Appstore SDK
  implementation 'com.amazon.device:amazon-appstore-sdk:3.+

  // Pull and compile the latest release of the Amazon Appstore SDK
  implementation 'com.amazon.device:amazon-appstore-sdk:+'

The next time you build your application, all the necessary files can be imported 
into your project.
 
C. Using Amazon Appstore SDK
Once you have integrated Amazon Appstore SDK with your Gradle project, you need to take the following steps:

1. Login to the Amazon developer portal (https://developer.amazon.com/login.html).
If you do not have an account, you will be prompted to create one.
2. Go to https://developer.amazon.com/apps-and-games/console/apps/list.html
3. Select your app or create a new one.
4. Get the Appstore public key
5. Add pem file to your project's assets folder.
6. Integrate and submit the app to Amazon Appstore.