HelloWorld activity Basic description of algorithm in step by step form: Create a HelloWorld Project. It will generate some default files like HelloWorld .java, main.xml, AndroidManifest.xml, Strings.xml. The AndroidManifest.xml defines an Activity which is the entry for any android application. An application can have at least one or more activity but every activity must be declared in AndroidManifest.xml The main.xml declares the user interface in XML. The strings.xml declares the text to be displayed in application. The HelloWorld class contains onCreate() method by default which is called when the activity is first created. In onCreate() method setContentView() method gets called which sets the view to setContentView (R.layout.main) by default. Here R is resource class of android which gets created automatically and which contains various layouts of the application in the form of xmls. Steps to Create: 1 Open Eclipse. Use the New Project Wizard and select And