UserSensor is a free and very simple real-time analytics product for your iPhone. The app delivers real-time information on a world map, showing where your users are visiting you from. Add your URL at usersensor.com for free and receive a 10-digit access number and a simple HTML tag. You add the tag to your website and enter the number on your iPhone. Seconds later, you can enjoy watching your real-time visitor information right on your phone, for free.