app.js

var get_file = function(url, callback) {
  var xhr = Ti.Network.createHTTPClient({
		onload: function(e) {
			// this function is called when data is returned from the server and available for use
			// this.responseText holds the raw text return of the message (used for text/JSON)
			// this.responseXML holds any returned XML (including SOAP)
			// this.responseData holds any returned binary data
			console.log('downloaded '+ url);
			
			callback({
				url: url,
				data: this.responseData
			});
		},
		onerror: function(e) {
			// this function is called when an error occurs, including a timeout
			console.log('error '+ url);

			callback({
				url: url,
				error: e.error
			});
		},
		timeout: 5000
		/* in milliseconds */
	});
	xhr.open("GET", url);
	xhr.send(); // request is actually sent with this statement
};



var files_arr = [
'http://farm6.staticflickr.com/5132/5502816868_67309ca2e6_o.jpg',
'http://farm5.staticflickr.com/4062/4398223914_8039585c48_o.jpg',
'http://farm6.staticflickr.com/5094/5416175148_3753a5cc90_o.jpg',
'http://farm9.staticflickr.com/8044/8124564455_66bf80d3b7_o.jpg',
'http://farm9.staticflickr.com/8301/7863005744_942b6c64d7_o.jpg',
'http://farm8.staticflickr.com/7300/9194232482_1cee5642e2_o.jpg'
];

var current_download = 0;

var callback = function(){
	current_download++;
	Ti.API.info( 'Downloading '+current_download+' of '+ files_arr.length);
	
	if ( current_download < files_arr.length) {
		get_file(files_arr[current_download], callback);
	}
};

get_file(files_arr[current_download], callback);