This paper describes the development of a mobile application to engage students in active learning in analytical chemistry. Colorimetry is a topic in analytical chemistry that can effectively be learned through the use of mobile devices to perform colorimetric measurement in the real-life environment. Previous attempts in the development of colorimetry mobile apps have been described in the literatures, however, shortcomings exist in their ease of use for teaching and learning and dissemination. We herein propose a colorimetry mobile app design that allows anyone to download, and easily perform colorimetric measurements and engage in active learning anytime, anywhere. Pedagogical underpinnings of the mobile learning activity and app design will also be discussed. [For the complete proceedings, see ED590271.]