Titanium.Network.HTTPClientでキャッシュを無効にする方法 ref: http://qiita.com/takuhou/items/5fb32d5a2f5f1942f2a3

file0.txt

App.Properties.getString("url", "http://XXXXXXXX.jp/app.json")

file1.txt

var client = Titanium.Network.createHTTPClient({
     onload : function(e) {
        // ------- // 
     },
     cache : false,
 });

file2.txt

client.setRequestHeader('Cache-Control','no-cache');
client.setRequestHeader('Cache-Control','no-store');