gistfile1.js

if (this.currentStep > this.numTutorialSteps) {
  Tutorial.tutorialScreen.classList.remove('show');
  Tutorial.tutorialFinish.classList.add('show');

  // for large devices, we have to use IAC to tell system ftu is done
  if (this.layout !== 'tiny') {
    navigator.mozApps.getSelf().onsuccess = function(evt) {
      var app = evt.target.result;
      app.connect('ftucomms').then(function onConnAccepted(ports) {
        ports.forEach(function(port) {
          port.postMessage('done');
        });
      }, function onConnRejected(reason) {
        console.log('FTU is rejected');
        console.log(reason);
      });
    };
  }
}