Core Java knowledge is recommended though.
Java and XML code snippets can be seen for each API example and Images for examples and outputs are also available to users for an easy understanding of the API stuff.
In the first part, A brief about Android OS and building blocks like Activities, Services, Broadcast Receivers, Content Providers are described.
Then comes the Android UI part that describes the widgets like Buttons, TextView, EditText, Radio Buttons, Listview, and various layouts like Relative Layout, Linear Layout, Absolute Layout, Table Layout, etc. It also covers Event Listener and Event Listener registration.
Then comes the Advanced Android concepts like Location Based Services that use GPS to know current location of any person, place etc. It covers Drag and Drop API that gives a good GUI feel to the end users. It also covers concepts like Notifications, Sending Email, Phone Calls, and Publishing Applications on Play Store!
The last section is Android Examples that has some important API examples like WebView for rendereing Webpages, SQLite Database for storing local data inside Android device, Facebook API support, JSON Parser API, Animations, Alert Dialogs, etc.