Abstract: This study examines the effectiveness of Kabitaru app in improving vocabulary acquisition among eleventh grade students at SLB B Yakut Purwokerto. Students with hearing loss often face challenges in acquiring English vocabulary due to limited exposure and lack of interactive learning tools. This study utilized a quantitative approach with a pre-experimental design, using a one-group pretestposttest method. The participants consisted of seven students who were assessed before and after using the Kabitaru app. Data analysis was conducted using paired sample test and N-Gain score calculation. The results showed a significant increase in students' vocabulary mastery, with an N-Gain value of 0.6263, classified as a moderate to high level of improvement. The paired sample test results (Asymp. Sig. = 0.042) confirmed the statistically significant difference between the pretest and posttest scores. These findings suggest that Kabitaru is an effective tool for improving vocabulary acquisition among students with hearing loss. This study suggests integrating technology-based learning applications in special education to foster a more engaging and accessible learning environment.