: To determine the effectiveness of the Amblyopia Treatment Chulalongkorn University (ATCU) application in improving compliance to occlusion therapy in amblyopic children. : We developed a smartphone application called Amblyopia Treatment Chulalongkorn University (ATCU), which includes education, patching calendar, mini-games, and notifications, offering caregivers a comprehensive tool to enhance amblyopia treatment adherence through informative content, interactive features, and personalized reminders. Children aged 4-12 years with strabismic, anisometropic, deprivation, or mixed-type amblyopia were recruited and randomly assigned to either use ATCU application to facilitate eye patching (group A) or receive standard care (group B). Compliance with eye patching (primary outcome) was measured as a percentage of actual patching hours which were subjectively reported by caregivers, compared to prescribed patching hours, assessed at 1 and 3-month follow-up. Secondary outcomes include best corrected visual acuity (BCVA). : Between October 2018 and December 2019, 45 children were enrolled in our study, with all meeting eligibility criteria. One participant was lost to follow-up, and only one child was newly diagnosed with amblyopia, while the others had undergone patching as a prior treatment. At 1-month, compliance was significantly higher in group A (85%) than in group B (64%) [median difference 22% (95% CI, 3 to 48;  = .037)]. At 3-months, the compliance was also higher in group A (80%) than group B (55%), but not significantly [median difference 13% (95% CI, -6 to 30;  = .096)]. BCVA improvement in group A was higher than group B at both follow-up periods [mean difference 0.04 logMAR (95% CI, 0.01 to 0.07;  = .025) at 1-month and 0.04 logMAR (95% CI, 0.01 to 0.08;  = .022) at 3-month follow-up]. : The ATCU application significantly improved compliance with occlusion therapy at 1-month. This application may be helpful as an adjunctive tool in the treatment of amblyopia.