Previous research has addressed the effects of digital storytelling (DST) on verbal English competence and demonstrated that students engage more and learn more effectively. However, the relationship between learner engagement and speaking competence needs a further analysis of the methods wherein a specific DST tool facilitates learner engagement in the learning process and how it influences their speaking skills. Therefore, this study employed Toontastic--an app with the principles of scaffolding embedded to assist learners in producing DST. Results indicated that learners made significant progress in speaking competence as regards fluency and language use; but no significant correlations were observed between learner engagement and fluency as well as between engagement and language use; and topic familiarity and scaffolding embedded within DST were the two major methods in which the app, Toontastic, supported learners in improving speaking competence and learning engagement. The study concluded that using DST helps learners successfully communicate. Implications are disscussed.