The Picture Viewer is completely an asynchronous application. When the user selects the start scanning option, the application starts to scan all of the subfolders asynchronously and stores every picture file that the phone can view. While scanning is still in progress the UI is still responsive so that user can view the pictures. The loading process of the picture file is also asynchronous. First the application checks if the file still exists than scales the picture, creates a new Bitmap file for the picture and views the picture without stopping the scanning process.