QBell instantly upgrades any front door with a powerful, fast and secure Smart-Doorbell interface. By replacing expensive hardware with our QR-code embedded units that require no installation, QBell is a useful, accessible and innovative answer to the problem of missed visitors and deliveries. We use patent-pending technology to create a realtime, anonymous connection between residents and visitors that maintains privacy, and requires no app to use as a visitor. World's smartest QR code doorbell technology.