Secondary school physical education (PE) teachers are continuously challenged to find ways to support students learning and motivate them for an active and healthy lifestyle. To address this complexity, continuing teacher professional development (TPD) is key. Technological tools can facilitate the effective delivery of TPD in this context. Successful implementation of this technology, however, is not self-evident. Based on the general aim of effectively integrating technologies in the educational process and focusing on the needs of educators, this study examines how the evidence-based theoretical TARGET framework for creating a motivating PE learning climate might be embedded into a digital professional development tool for PE teachers, useful in everyday practice. It presents a case study in which a multidisciplinary team of researchers, designers, and end-users iteratively went through several phases of need identification, idea generation, designing, development, and testing. By using a participatory approach, we were able to collect contextualized data and gain insights into users’ preferences, requirements, and ideas for designing and engaging with the tool. Based on these insights the TPD TARGET-tool for PE teachers was ultimately developed. The most prominent characteristics of this tool are (1) the combination of an evaluative function with teaching strategy support, (2) the strong emphasis on ease of use due to the complex PE teaching context, (3) the avoidance of social comparison, and suggestions of normative judgment, and (4) the allowance for a high level of customization and teacher autonomy.