The objective of this project was to address design gaps in previous programs that address scientific argumentation in middle schools. We adopted gamification mechanics (e.g., stimulus and response and progression) to design a computer-assisted program to better support students' development of scientific argumentation. In this paper, we describe the development of a gamified tool to support the representation of collaborative scientific argumentation for middle school students and describe how a faculty member in the Instructional Technology program and a faculty member and students in the Department of Computer Science collaborated and delivered project work through the Agile methodology. We developed two iterations of the prototype and conducted usability tests of the two iterations of the design with adults and middle school students in the United States. This study presents how the design evolved from the first to the second iteration based on usability testing results. The adult participants (e.g., science pre-service teachers and an in-service teacher) and student participants provided suggestions for further improvement of the second iteration of the prototype.