Given the complexity of teaching, continuing teacher professional development (CPD) is essential for maintaining and enhancing teaching effectiveness, and bridging the gap between ever-evolving theory and practice. Technological advancements have opened new opportunities for digital tools to support CPD. However, the successful integration of such digital tools into practice poses challenges. It requires adherence to CPD prerequisites and acknowledgment of the complexity of the professional development process. This study explored the applicability of the developed digital PE teacher professional development TARGET-tool in a secondary school PE context. We examined the perceived usability of this tool and gained insights into the process of teachers' professional development as a result of using the tool. Ten PE teachers from different schools implemented the TARGET-tool within their PE context for a period of 4 to 6 weeks. Individual semi-structured interviews and the System Usability Scale provided insights into the perceived usability and the process of teacher professional development. The TARGET-tool demonstrated its potential as an effective tool for supporting teachers' professional development. Future tool improvements were identified to further optimize the perceived usability, such as simplifying complex features, providing additional support and resources, and improving (data) presentations. Using the Interconnected Model of Professional Growth as a theoretical basis, it was demonstrated how the use of the TARGET-tool engages teachers as active and reflective participants in their professional development and induces changes within the external domain, the domain of practice, the domain of consequences, and the personal domain.