Digital books provide a variety of ways to convey story content through the combination of images, text and audio. To effectively apply this combination to improve toddlers’ positive self-expression and social communication abilities, though, relatively little experience and knowledge is available. We propose a “Users+” model to address this issue. By expanding the current design, we introduce the user into the design aspect of the application, replacing textual content with children’s perception and interpretation of images. We investigated the “Users+” model’s application using Babbling, a wordless digital book for kids. We explore the function of digital book applications in children’s self-expression and interpersonal interactions and the value of the text for children’s reading through a study of the behaviors and emotions of 20 preschoolers while reading. Thereby, we summarize three design strategies that provide a new insight into children’s digital book applications that support user engagement and autonomy in design.