The aim of this study is to develop a gamified library orientation mobile application. The study is conducted with design based research method. Considering the "Analysis and Exploration" and "Design and Construction" cycles of the generic model of McKenney and Reeves (2012) for conducting design research in education, a prototype is developed which is based on the literature review, documentation analysis, and interviews with three librarians. After the "Evaluation and Reflection" cycle, an improved version is designed and developed. The sixth and the latest version of the application is developed following the completion of five meso-cycles of Design Construction - Evaluation - Reflection. In this process, the prototype is updated in accordance with the opinions of three distinct experts for gamification, the content of library orientation, and usability of the application. In addition, the inputs of two user tests carried out with the participation of 7 students are used to improve the design. In this task-based application, point, reward, level, badge, dashboard, and leaderboard game elements were used. While the application proposal is specialized for the Hacettepe University Beytepe Library, it is expected to be helpful to researchers and practitioners by explaining both the design and its development process.