These should be stored in your sites' home directory, unless the path is specified in the HTML using the below code.
The tool will output four png's, with dimensions of 57x57 (iPhone), 72x72 (iPad), 114x114 (iPhone Retina) and 144x144 (iPad Retina). If this file is not found these Apple products will use the screen shot of the web page, which often looks like no more than a white square. When someone bookmarks your web page or adds your web page to their home screen this icon is used. Similar to the Favicon, the apple-touch-icon.png is a file used for a web page icon on the Apple iPhone, iPod Touch, and iPad.
