Mobile applications have thoroughly pervaded the lives of today's children, who live and learn through and with them. However, limited research has been conducted on children designing such apps and not only using those designed by adults. Inviting children to design such apps is the focus of our study. Moreover, in contemporary society, it is emphasized that children should be empowered to take civic action and engage in making the world a better place. In the literature, however, less emphasis has been placed on how children can be invited to do so through the means of digital technology, particularly mobile application design. In this study, 13–15-year-old children are invited to take civic action to address the serious societal problem of bullying through the design of mobile apps. We discussed the design process and analyzed the applications the children designed from the viewpoint of how they aim to tackle bullying. We examined how their app designs aim at empowering other children in the context of bullying, and thus considered what kinds of opportunities emerge for children to learn skills related to the prevention or management of bullying in the apps they have designed. We showed that the children's app designs informed us of the seriousness of bullying in children's lives and that they advocate for the empowerment of other children in different ways. Hence, we have increased our understanding of how smart, interactive technologies designed by children address the learning and empowerment of other children, i.e., application users. We also studied the children's learning from both their and their teachers' perspectives. This study showcases an alternative way educators can integrate digital technologies and apps in school settings to educate children on important societal matters and digital technology.