Downloadable software and software applications permitting users to identify and communicate with persons at their door; downloadable software and software applications permitting users to monitor their home, office, and other facilities; downloadable applications for monitoring a user's home, office, and other facilities, for use over the Internet, mobile devices, wireless Internet networks or systems, and other computer and electronic communication networks; software and software applications permitting users to monitor the interior and exterior of homes, retail stores, or offices for security and surveillance; downloadable software and software applications for monitoring a user's home, office and other facilities, for use over the Internet, mobile devices, wireless Internet networks or systems and other computer and electronic communication networks