During this tutorial, we’ll develop a working Twitterlike application capable of posting status updates to the cloud as well as pulling the data from the cloud so we can see what our friends are up to. Along the way, you will learn about main building blocks that make up an Android app, such as activities, services, provides and receivers. We’ll focus on UI by building couple of screens and services to process background network tasks. You will also learn about concurrency issues in Android. During this tutorial, you will get to experience building an app from the ground up. You will get to see how Android tools work, and how to use the tools to develop, and debug the application.
This tutorial is from Android Up and Running talk at OSCON 2013