Since file uploads are done to the folder APPLICATION_PATH/uploads, the application tries to create this folder if it does not exists. For this reason APPLICATION_PATH should be writable, or uploads folder created manually with necessary rights. The application also requires 'uploadprogress' PECL package since it uses 'uploadprogress_get_info' function for getting the information about upload progress.
The source code is at GitHub. Most action happens in indexController.php and index.phtml.
