In this paper, we present an innovative software system called Preferences Monitoring that makes use of modern middleware technologies and available hardware and communication systems. People can use the system to easily buy products that fit with their preferences. The system consists of mobile-phone side to scan product barcodes, submit user inquiries to a server, and display results. Results are related to whether users can eat or drink the product based on their preferences such as religion (no meat, beef, pork, or wine), or based on health settings such as allergies, chronic diseases or calories. Also, the system includes web services to facilitate user access to online profiles for editing accounts, viewing history-shopping and subscribing to other services. The preliminary results of testing our system show that the system can provide useful services for consumers. We also highlight some technical issues that are related to reading barcode using mobile phones.