Interactivity is an important indicator of an educational app's reception. Since most educational apps are multimodal, it justifies a methodological initiative to understand meaningful involvement of multimodality in enacting and even amplifying interactivity in an educational app. Yet research so far has largely concentrated on algorithm construct and user feedback rather than on multimodal interactions, especially from a social semiotics perspective. Drawing from social semiotics approaches, this article proposes a multimodal analytic framework to examine three layers of mode in engendering interaction; namely, multiplicity, function, and relationship. Using the analytic framework in an analysis of The Farm Adventure for Kids, a popular educational app for pre-school children, we found that still images are dominant proportionally and are central in the interactive process. We also found that tapping still images of animals on screen is the main action, with other screen actions deliberately excluded. Such findings suggest that aligning children's cognitive and physical capabilities to the use of mode become the primary consideration in educational app design and that consistent attendance to this alignment in mobilizing modes significantly affect an educational app's interactivity, and consequently its reception by young children.