Teamwork, one of the core competencies for the twenty-first century learner, is a critical skill for work and learning. However, assessing teamwork is complex, in particular, developing a measure of teamwork that is domain-generic and applicable across a wide range of learners. This paper documents one such study that leverages technology to help provide a formative assessment of teamwork. It focuses on the self and peer ratings of a teamwork measure and a pedagogical method, which was trialled as a teamwork awareness programme in a mainstream Secondary School in Singapore. This teamwork awareness programme was incorporated into the school's Interdisciplinary Project Work curriculum. Findings of students' experiences of the programme are described. The teamwork competency dimension of "team emotional support" was rated highest amongst students. Also, students' report gains in teamwork awareness, mixed engagement in reflective practices, and on the real-world relevancy of the programme. Discussions and implications of the findings follow.