Nowadays, mobile learning utilizing mobile applications has become widely adopted due to its flexibility and the numerous benefits it offers. However, the availability of mobile apps in education especially for assessment is limited and still an emerging topic despite the affirmation of its positive impact on students’ learning outcomes and motivation. The complexity of the mobile application development process, which includes requirement elicitation, modeling, designing, developing, testing, and evaluating, could be a contributing factor to this issue. This study aimed to propose a guideline for designing and developing an educational mobile application through the development of an application named IsMind that focuses on formative assessment. Evolutionary Prototyping, a methodology under the agile approach of Software Development Life Cycle (SDLC) was deployed to meet the educational application requirement by integrating content, pedagogy, and technology aspects to provide better teaching and learning material. The activities within each phase of evolutionary prototyping including the models, tools, techniques, and deliverables were discussed extensively. The analysis and design phase were done using an object-oriented approach with appropriate models (diagrams) to present the functional requirement of the mobile application. Various CASE tools which accelerated the development process in various stages of software development were explained.UMLet software was employed to create a use case diagram, activity diagram, and sequence diagram. The user interface design, which followed The Eight Golden Rules of Interface, was developed utilizing Marvel software. Adobe Photoshop CS6, Adobe Illustrator CS6, Unity 3D, and Microsoft Visual Studio Code (C#) were utilized in the development process. The mobile application provides a variety of question types, such as Drag And Drop, Multiple Choice, Numbering, True And False, Matching, and Puzzle. The evaluation of IsMind indicated its appropriateness as an interactive teaching and learning media for assessment. The proposed steps for constructing this assessment educational mobile app. The proposed methodology consists of the details of phases, various activities within each phase, techniques, models, and tools for each activity as well as deliverables of each phase offer a helpful guideline for anyone interested in developing a similar application.