Account manager
In the context of storing sensitive data, storing passwords or authentication tokens is an important aspect. Consider applications such as Google Mail, Twitter, and Facebook, which lets users log in. Other applications work with an authentication token as used by identity protocols such as OAuth2.
Android provides the android.accounts.AccountManager class as a centralized repository for storing user credentials. An application can choose to use its own pluggable authenticator to handle account authentication. From storing the username to identity information to creating your custom account manager, Android's AccountManager is a powerful utility.
The AccountManager class functions are permissions protected so that your application will have to request for android.permission.GET_ACCOUNTS to access the list of accounts stored on it and android.permission.ACCOUNT_MANAGER for OAuth2.
Each account is in a namespace format. For example, a Google account uses com.google and a Twitter...
