Introduction: This study aimed to develop a new tablet application named the Aid for Decision-making in Occupation Choice for School (ADOC-S). It aims to assist with conducting collaborative occupation-based goal-setting by sharing decision-making with a team member (child, parent, teacher, and occupational therapist) using a consultation model of school-based occupational therapy (SBOT). Method: This developmental study involved two phases: (1) using a focus group technique to develop the concept and prototype of the ADOC-S, and (2) using a Delphi-style method to reach a consensus among eight experienced occupational therapists regarding the ADOC-S items, text, and images. Then, we reported its use in SBOT practice with a single case example of a school-aged child in Japan. Results: First, the concept and the prototype application of ADOC-S was created. Then, after two Delphi rounds, the eight occupational therapists reached a consensus that 68 items in four categories were included in the ADOC-S: Self-care (17 items); Communication (9 items); School life (22 items); and Play (20 items). The case study illustrated how to use the ADOC-S and its efficacy for collaborative goal-setting in SBOT. Conclusion: The ADOC-S appears to promote collaborative goal-setting in SBOT. This application now needs to be clinically tested.