Declare that this application requires an account of a certain type. The default value is null and indicates that the application can work without any accounts. The type should correspond to the account authenticator type, such as "com.google".

Must be a string value, using '\\;' to escape characters such as '\\n' or '\\uxxxx' for a unicode character.

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

[Android Documentation]