The proliferation of smart communication devices based on technologies such as Radio-Frequency IDentification (RFID) makes ubiquitous computing evolving at a frantic pace. This evolution leads to the development of applications, called \textit{monitoring applications}, that offer a host of new functionalities based on context information provided by tagged entities. In this paper, we introduce a software architecture dedicated to monitoring applications and define a mapping to the Amigo middleware which is dedicated to ambient computing. We illustrate our approach by developing two real-size applications for child monitoring and object reminder. In these experiments, our approach have demonstrated its usability and ease of programming.