This thesis discusses the development of mobile based application which is used by the customers of department store XYZ. XYZ is a fashion department store originated abroad which has just opened its new branch in Indonesia. In this new branch, XYZ especially would like to encourage customers to use Loyalty card during the transaction, while also carrying out marketing strategies such as giving out promotions and rewards to customers. The proposed application is intended to address this issue, which serve as a transaction media that supports the use of non-physical Loyalty card, and as a marketing media for department store XYZ to be able to deliver valuable information or benefits to the customer. This mobile application is developed with Agile methodology that implements Scrum method. The development includes gathering and analyzing requirements, managing tasks, modeling the application using UML 2.0., and constructing the application using Java and Android SDK. It is followed with reviewing and testing the application using black-box testing with integration and user acceptance test approach. As the result, the proposed application supports customer’s transaction with non-physical Loyalty card through the use of QR code technology. It also enables company to deliver promotions and reward to specific loyalty card owner which can be redeemed during transaction. Moreover it helps company to deliver information of news, events, brands, catalogue and promotions to all customers who use this application.