createActivityIndicator

app.js

Ti.UI.backgroundColor = 'white';

var win1 = Ti.UI.createWindow({
	backgroundColor : 'white'
});

var win2 = Ti.UI.createWindow({
	backgroundColor : 'yellow'
});

var activityIndicator = Ti.UI.createActivityIndicator({
	color : 'green',
	message : 'Loading ...',
	style : Ti.UI.ActivityIndicatorStyle.DARK,
	top : 100,
	left : 100,
	height : Ti.UI.SIZE,
	width : Ti.UI.SIZE
});

// The activity indicator must be added to a window or view for it to appear
win2.add(activityIndicator);

// eventListeners must always be loaded before the event is likely to fire
// hence, the open() method must be positioned before the window is opened
win2.addEventListener('open', function(e) {
	activityIndicator.show();
	// do some work that takes 6 seconds
	// ie. replace the following setTimeout block with your code
	setTimeout(function() {
		for (var i=40000; i>0; i--)
        Ti.API.info("Test: "+i); 
		e.source.close();
		activityIndicator.hide();
	}, 6000);
});

win1.open();
win2.open(); 

new.js

win2.addEventListener('open', function(e) {
	activityIndicator.show();
	setTimeout(function() {
		for (var i=40000; i>0; i--){
			Ti.API.info("Test: "+i); 
		}
		activityIndicator.hide();
		e.source.close();
	}, 6000);
});