A repeated acquisition (RA) design was used to compare the effectiveness of research-based instruction embedded in repeated storybook reading facilitated by an adult or tablet application (app) on the vocabulary knowledge of six preschool children. All participants selected scored below the 40th percentile on the "Preschool Language Scale--Fifth Edition." Three target verbs frequently encountered in speech and text (Tier 2) from 16, age-appropriate storybooks were selected. Definitions of the target verb, multiple contextualized examples, and demonstrations of the verb action were taught. All children benefited from the intervention in both conditions, but increases were higher for four participants in the app condition, and modest for two participants in both conditions. Depth of knowledge was assessed using a scoring rubric, and four children increased their ability to provide multiple examples or a definition of the word. Implications for research and practice are discussed.