an android app in 64 lines of code

$ cat app.js
// this sets the background color of the master UIView (when there are no windows/tab groups on it)
Titanium.UI.setBackgroundColor('#000');

// create tab group
var tabGroup = Titanium.UI.createTabGroup();

//
// create base UI tab and root window
//
var win1 = Titanium.UI.createWindow({
    title:'Tab 1',
    backgroundColor:'#fff'
});
var tab1 = Titanium.UI.createTab({
    icon:'KS_nav_views.png',
    title:'Tab 1',
    window:win1
});

var label1 = Titanium.UI.createLabel({
    color:'#999',
    text:'I am Window 1',
    font:{fontSize:20,fontFamily:'Helvetica Neue'},
    textAlign:'center',
    width:'auto'
});

win1.add(label1);

//
// create controls tab and root window
//
var win2 = Titanium.UI.createWindow({
    title:'Tab 2',
    backgroundColor:'#fff'
});
var tab2 = Titanium.UI.createTab({
    icon:'KS_nav_ui.png',
    title:'Tab 2',
    window:win2
});

var label2 = Titanium.UI.createLabel({
    color:'#999',
    text:'I am Window 2',
    font:{fontSize:20,fontFamily:'Helvetica Neue'},
    textAlign:'center',
    width:'auto'
});

win2.add(label2);

//
//  add tabs
//
tabGroup.addTab(tab1);
tabGroup.addTab(tab2);  

// open tab group
tabGroup.open();