Recent calls to improve the quality of education in schools have drawn attention to the importance of teachers’ preparation for work in classroom settings. Although the practicum has long been the traditional means for pre-service teachers to learn and practice classroom teaching, it does not always offer student teachers the time, safe practice experiences, repetition, or extensive feedback needed for them to gain adequate knowledge, skills, and confidence. Well-designed simulations can augment the practicum and address these gaps. This study evaluated the design of simSchool (v.1), an online simulation for pre-service teachers, using student teachers’ ratings of selected factors, including realism, appropriateness of content and curriculum, appropriateness for target users, and user interaction. Based on these ratings, the study identified strengths and weaknesses, and suggested improvements for the software. Participant ratings varied considerably but indicated that certain aspects of the simulation, such as its educational value, classroom challenges, and simulated student characteristics, were moderately well received. However, user interface navigation and the range and realism of simulated teacher–student interactions should be improved.