This article proposes an Internet of Things–based smart home system composed of a virtualized cloud server and a mobile phone app. The smart Internet of Things–based system includes a sensing network, which is developed with the ZigBee wireless communication protocol, a message queuing telemetry transport, a virtualized cloud server and a mobile phone app. A Raspberry Pi development board is used to receive packet information from the terminal sensors using ZigBee wireless communication. Then, the message queuing telemetry transport broker not only completes transmission of the message but also publishes it to the virtualized cloud server. The transmission can then be viewed through the website using a mobile phone. The designed app combines the application of the virtualized cloud server, client sensors and the database. Verification experiments revealed the measured average response time and throughput of approximately 4.0 s and 6069 requests per second, respectively, for the virtualized web server and approximately 0.144 s and 8866 packets per second, respectively, for the message queuing telemetry transport broker. The designed functions of the mobile phone app are a global positioning system home monitoring, family memo, medical care and near-field communication key. Both interlinkage and handler methods are proposed to facilitate a powerful function without delay in displaying information. The proposed system integrates with software and hardware to complete the data analysis and information management quickly and correctly. It can cater to user needs with superior ease and convenience.