It adds the following features:
View Stats on the Go
Stylize Your Text with the Visual Editor
Moderate Multiple Comments at Once
Stats tab for WordPress.com blogs and self-hosted that are using the WordPress.com stats plugin added.
Bulk comment moderation (select ‘edit’ on the comments tab).
Better video embedding for self-hosted blogs.
WordPress for Android is an Open Source app that empowers you to write new posts, edit content, and manage comments with built-in notifications.
More info: http://android.wordpress.org/