The demo system is an area you can use to get a feel for billster before registering for a free account. It is fully functional appart from three things, emails aren't sent, logout doesn't actually log you out and the system will reset itself every hour. Don't be affriad to get your fingers dirty, try adding, modifying and deleting stuff and if you like what you see, register for an account. See something you don't like, give us your feedback.