Recuperando um arquivo utilizando a Web API do FFOS

getfile.js

var sdcard = navigator.getDeviceStorage('sdcard');

var request = sdcard.get("my-file.txt");

request.onsuccess = function () {
  var file = this.result;
  console.log("Get the file: " + file.name);
}

request.onerror = function () {
  console.warn("Unable to get the file: " + this.error);
}