Why can't I fit my AIR app to the screen of the device ??

Question

Hi all,
I've made some apps on device but it's the first time that I can't make the app fit the screen and I really don't understand why.
I've downloaded an exemple of the game Flappy bird and I would like to play with my device.
Can you help me make the app fit the device screen please ?
Here's my main.as
package{
  import citrus.core.starling.StarlingCitrusEngine;
    import flash.display.Stage;
  import flash.events.*;
    import flash.display.StageAlign;
   import flash.display.StageScaleMode;
  [SWF(frameRate="60")]
  public class Main extends StarlingCitrusEngine {
  public function Main() {
        stage.align = StageAlign.TOP_LEFT;
  stage.scaleMode = StageScaleMode.EXACT_FIT;
  override public function initialize():void {
  setUpStarling();
  //starling is ready, we can load assets
  override public function handleStarlingReady():void
  state = new FlappyBirdGameState();
Here's my FlappyBirdGameState.as :
public function FlappyBirdGameState()
  super();
  override public function initialize():void
  super.initialize();
  ce = CitrusEngine.getInstance();
  // load assets, then draw screen
  loadAssets();
  // fly with the spacebar, alternatively
  kb = ce.input.keyboard;
  kb.addKeyAction("fly", Keyboard.SPACE);
  private function loadAssets():void {
  assets = new AssetManager();
  assets.verbose = true;
  assets.enqueue(Assets);
  assets.loadQueue(function(ratio:Number):void
  trace("Loading assets, progress:", ratio);
  if (ratio == 1.0)
  // add game elements
  drawScreen();
  private function drawScreen():void
  var bg:CitrusSprite = new CitrusSprite("bg", {x: 0, y: 0, width: 320, height: 480});
  bg.view = new Image(assets.getTexture("bg.png"));
  add(bg);
  box = new CitrusSprite("box", {x: 40, y: -200, width: 240, height: 200});
  box.view = new Image(assets.getTexture("box.png"));
  add(box);
  textField = new TextField(200, 200, "CLICK TO FLY", "Flappy", 20, Color.NAVY);
  textField.x = 60;
  textField.y = -200;
  addChild(textField);
  // box and textField have synced tweens
  eaze(box).to(0.4, { y: 150 } );
  eaze(textField).to(0.4, { y: 150 } );
  ce.stage.addEventListener(MouseEvent.MOUSE_DOWN, start);
  function start(e:MouseEvent):void
  eaze(box).to(0.2, { y: -200 } );
  eaze(textField).to(0.2, { y: -200 } );
  newGame();
  ce.stage.removeEventListener(MouseEvent.MOUSE_DOWN, start);
  public function newGame():void
  // get a random Y position for first pipe
  randomizePipeY();
  pipe1 = new CitrusSprite("pipe", {x: 380, y: pipeY, width: 60, height: 160});
  pipe1.view = new Image(assets.getTexture("pipe.png"));
  add(pipe1);
  pipeBoundsTop1 = new Rectangle(0, 0, 50, 355);
  pipeBoundsBottom1 = new Rectangle(0, 0, 50, 364);
  // get a random Y position for second pipe
  randomizePipeY();
  pipe2 = new CitrusSprite("pipe2", {x: 620, y: pipeY, width: 60, height: 860});
  pipe2.view = new Image(assets.getTexture("pipe.png"));
  add(pipe2);
  pipeBoundsTop2 = new Rectangle(0, 0, 50, 355);
  pipeBoundsBottom2 = new Rectangle(0, 0, 50, 364);
  // the character
  thing = new CitrusSprite("thing", {x: 100, y: 200, width: 40, height: 50});
  thingImage = new Image(assets.getTexture("thing.png"));
  thing.view = thingImage;
  add(thing);
  thingBounds = new Rectangle(0, 0, 35, 45);
  ce.stage.addEventListener(MouseEvent.MOUSE_DOWN, fly);
  // move box to top
  var container:Sprite = view.getArt(box).parent;
  container.swapChildren(view.getArt(box) as DisplayObject, view.getArt(pipe1) as DisplayObject);
  container.swapChildren(view.getArt(box) as DisplayObject, view.getArt(pipe2) as DisplayObject);
  container.swapChildren(view.getArt(box) as DisplayObject, view.getArt(thing) as DisplayObject);
  // score text field
  scoreText = new TextField(300, 50, "", "Flappy", 20, Color.NAVY);
  scoreText.hAlign = "right";
  scoreText.x = -10;
  scoreText.y = 0;
  addChild(scoreText);
  // a few more things
  clicked = true;
  score = 0;
  velocity = -7;
  // click to fly
  public function fly(e:MouseEvent):void
  velocity = -7;
  assets.playSound("whoosh");
  // get a new Y position for a pipe
  private function randomizePipeY():void
  pipeY = new Number(Math.floor(Math.random() * -330) + -40);
  override public function update(timeDelta:Number):void
  super.update(timeDelta);
  if (clicked)
  if (!gameOver)
  // move pipes
  pipe1.x -= 2;
  pipe2.x -= 2;
  // after pipes go off screen, move them
  if (pipe1.x <= -60)
  //randomize pipe Y
  randomizePipeY();
  pipe1.x = 380;
  pipe1.y = pipeY;
  if (pipe2.x <= -60)
  // randomize pipe Y
  randomizePipeY();
  pipe2.x = 380;
  pipe2.y = pipeY;
  // fly through a pipe, gain a point
  if (pipe1.x == thing.x || pipe2.x == thing.x)
  score++;
  scoreText.text = String(score);
  assets.playSound("ding");
  // spacebar to fly
  if (ce.input.justDid("fly"))
  if (!gameOver)
  velocity = -7;
  assets.playSound("whoosh");
  // character falls with gravity
  velocity += gravity;
  thing.y += velocity;
  // prevent flying through the top and bottom of screen
  if (thing.y <= 0)
  thing.y = 0;
  if (thing.y >= 430)
  thing.y = 430;
  // collision
  thingBounds.y = thing.y + 2.5;
  thingBounds.x = thing.x + 2.5;
  pipeBoundsTop1.x = pipe1.x + 5;
  pipeBoundsTop1.y = pipe1.y;
  pipeBoundsBottom1.x = pipe1.x + 5;
  pipeBoundsBottom1.y = pipe1.y + 495;
  pipeBoundsTop2.x = pipe2.x + 5;
  pipeBoundsTop2.y = pipe2.y;
  pipeBoundsBottom2.x = pipe2.x + 5;
  pipeBoundsBottom2.y = pipe2.y + 495;
  // lose the game
  if (thingBounds.intersects(pipeBoundsTop1) || thingBounds.intersects(pipeBoundsBottom1)
  || thingBounds.intersects(pipeBoundsTop2) || thingBounds.intersects(pipeBoundsBottom2))
  die();
  // death, show score and click to play again
  private function die():void
  if (!gameOver)
  gameOver = true;
  assets.playSound("smack");
  ce.stage.removeEventListener(MouseEvent.MOUSE_DOWN, fly);
  // prevent clicking briefly to let the player see their score
  var t:Timer = new Timer(500, 1);
  t.addEventListener(TimerEvent.TIMER_COMPLETE, cont);
  t.start();
  function cont(e:TimerEvent):void
  textField.text = "Score: " + score;
  scoreText.text = "";
  eaze(box).to(0.4, { y: 150 } );
  eaze(textField).to(0.4, { y: 150 } );
  ce.stage.addEventListener(MouseEvent.MOUSE_DOWN, startOver);
  // reset everything, start the game again
  private function startOver(e:MouseEvent):void
  eaze(box).to(0.2, { y: -200 } );
  eaze(textField).to(0.2, { y: -200 } );
  score = 0;
  pipe1.x = 380;
  pipe2.x = 620;
  thing.x = 100;
  thing.y = 200;
  velocity = 0;
  gravity = 0.4;
  gameOver = false;
  randomizePipeY();
  ce.stage.removeEventListener(MouseEvent.MOUSE_DOWN, startOver);
  ce.stage.addEventListener(MouseEvent.MOUSE_DOWN, fly);
Thanks,

Answer 1

Yeah, it should. But, weirdly, it's not...
Here's what I see on the device emulator with Adobe Flash Pro :
And here's what I see when I install the apk on my Android device :
Can't understand why it's happening.
The game was in an example package of the citrus engine : https://drive.google.com/file/d/0B5-MjJcEPm3lMU5jSzB0dDBualk/view?usp=sharing