In this study, we explore teacher perspectives on the utility of a formative assessment tool, Teacher RePlay, to support their implementation of learning through play (LTP) activities in classrooms for students age 3 to 12 years in Bangladesh, Colombia, and Uganda. Research suggests that formative assessment tools may be useful to bridge support from professional development trainings to the classroom. The Teacher RePlay tool was designed to provide continued support to teachers subsequent to their participation in training sessions on implementing LTP. Through interviews, we explored the benefits and challenges teachers experienced while using the tool. Teachers reported the tool improved their planning and delivery of LTP activities and cited positive outcomes, including enhanced student engagement, attendance, and overall learning. Challenges in implementing LTP included class size limitations, time constraints, and technology access. The study underscores the importance of considering cultural contexts in implementing LTP and suggests future considerations, including alternative resource delivery formats and the creation of a support community for teachers. We highlight, as an alternative to the traditional professional development model, the promise of formative assessment tools as a means of providing continual and productive support to teachers.