RESUMEN
BACKGROUND: This study aimed to describe the acceptability and feasibility of the “HAPPY ME”, a smartphone application (app) for guiding healthy eating habits and physical activities to prevent childhood obesity, through in-depth interviews of 5th and 6th grade students of an elementary school. METHODS: A total of 25 students were recruited from grades 5 and 6 of an elementary school in Gimpo. They were asked to participate in in-depth interviews about expectations regarding the “HAPPY ME”, smartphone usage behaviors, perceptions and attitudes towards health, and satisfaction with the “HAPPY ME”, before and after the 4-week trial of the “HAPPY ME”. RESULTS: Study participants reported a high level of satisfaction regarding gamification elements such as awarding points as rewards for completing missions and using closed social networking services with friends. They also reported that their eating habits had improved after the 4-week trial. However, some students felt that the app was complicated to use and recommended that it should have prompts as notifications. CONCLUSIONS: This study showed that the “HAPPY ME” is acceptable and feasible for use with children. However, the app needs to be modified based on the results of this study.