Purpose: To develop the storyboard of IACTA further, based on the child’'s perspective, by testing and evaluatingboth re-designed and newly designed scenes.Design andmethod: A participatory designwas used involving preschool children (n=18) aged three to fivewhotested and evaluated evolving prototypes of the IACTA application. Think aloud and Active intervention wereused to elicit verbal responses from the children. Additionally, observational protocols were used to capture, ina structured way, the children's interaction with the app.Results: By testing evolving prototypes, the children confirmed previous developments and challenged the newlyadded scenes of the app. By their interaction, important information regarding the children's ways of navigatingthe storyboard was obtained.Ways of becoming immersed in the storyboard and the eagerness of dealing witheach scene provided information regarding likeability.Conclusions: Overall, this article presents a participatory design process in which preschool aged children wereinvolved in testing and evaluating prototypes of the re-designed IACTA app. In the process, the children providedtheir perspective on the design and content and eventually, based on their feedback, IACTA was proven to be anage-appropriate tool.Practical implications: Children are frequent visitors to healthcare services. Lack of knowledge might trigger fearand anxiety, whereas information provides understanding. Interactive, mobile solutions enable children to receiveinformation within paediatric healthcare contexts. The IACTA application intends to provide children a situatedunderstanding that facilitates their participation in healthcare situations.