Abstract: The assembly comprises a first subassembly of sensing Smartphones, such as Android Smartphones and iPhone Smartphones, the first subassembly of sensing Smartphones incorporating Wi-Fi sensors and Bluetooth sensors for sensing Smartphones identifiers; a second subassembly incorporating an internet; a third subassembly for storing and conveying messages using a push server with specially developed software for communicating over the second subassembly with the first subassembly; the third subassembly been adapted to be controlled by an operator; a forth proprietary messaging server subassembly for further transmitting messages received over the second subassembly from the third subassembly and pushed to the sensing Smartphones using the second subassembly, namely to each sensing Smartphone; the forth proprietary messaging server subassembly incorporating a Google Cloud Messaging server or an Apple Push Network server and a Cellular Data Network.