The purpose of the article is to describe and problematise the practice-initiated idea of developing a digital tool for children in child welfare investigations and whether and how this welfare technology is useful for social workers. The results include interview data and descriptions of the research process. The social workers are of the opinion that the digital application increases the possibilities for children’s participation in child investigations, even though their main focus is to create an alliance with the parents. During the research process the digital tool has developed from an empirical idea to a conversation tool and been tested with different user groups. However, the law on procurement limits the possibilities for data storage if the digital tool is to be used in the future. In sum, in order to develop child protection work further, more practice-based research needs to be conducted so that researchers can develop the practice’s ideas and identify the obstacles, opportunities, organisational conditions and development needs. The social workers in this study believe that the digital tool is useful for accessing children's perspectives and experiences, even though relational work with children is not their main task in child welfare investigations.