The results in this article explore whether and how the design of applications used on tablet computers influences the interaction and dialogues that occur between children and pedagogues, the participation of children in the activities and the mathematics that can be learned. While mathematics offered a lens to explore the use of tablet devices, child--teacher interactions is the focus of this article. Twelve pedagogues were observed as they used different applications with 25 preschool children. These applications were categorised based on their classification (boundaries of the application) and framing (form of the application). It was shown that the same pedagogue interacted differently with the children based on the application they were using. Further, the children's participation as well as the structure and content of the dialogues between pedagogues and children differed based on classification and the framing of the application used. The results indicate that the design of the applications influences the pedagogues and the educational context in which children are invited to participate.