Introduction: Excessive consumption of sugar-sweetened beverages (SSBs) drives obesity, diabetes, and metabolic diseases, yet awareness of Indonesia›s daily sugar limits remain low and digital tools to track intake against national guidelines are scarce. This study developed and validated EduDrink, a mobile app for monitoring SSB intake, through expert review and user testing of its content, design, and usability. Methods: EduDrink was developed using a research-and-development approach comprising four stages: SSB data collection, system and interface design, educational video development, and usability evaluation. System requirements were modelled using Unified Modelling Language (UML), while the interface was designed in Figma. Functional features were tested using black-box testing. Usability evaluation was conducted using a mixed-methods approach, including focus group discussions with experts that were analysed using thematic analysis and intercoder reliability, including percent agreement and Gwet’s AC. User Acceptance Testing (UAT) involved 58 urban users aged 19–40 years. Results: Expert evaluation identified five key themes: alignment with guidelines, clear design, user-friendliness, accurate portionto-sugar conversion, and adequate data security. Intercoder reliability showed almost perfect agreement (97.4%; Gwet’s AC=0.945). UAT results demonstrated high acceptance, with over 85% of indicators rated “Good”, particularly for information validity, sugarmonitoring features, and video-based education. Conclusion: EduDrink is a usable and feasible mobile health application for monitoring SSB consumption among urban young adults in Indonesia. Its features support dietary self-monitoring and boost sugar intake awareness, but its effect on lasting behavioural change and health outcomes still needs testing in future controlled studies.