SLEEP follows a standard procedure of using log files. These files log visitors when they use app. The information collected by log files include internet protocol (IP) addresses, browser type, Internet Service Provider (ISP), date and time stamp, referring/exit pages, and possibly the number of clicks. These are not linked to any information that is personally identifiable. The purpose of the information is for analyzing trends, administering the app, tracking users' movement on the app, and gathering demographic information.