Background <p>Family Caregivers (FC) make a significant contribution to maintaining our care system and must be supported in their vital roles. Alles Clara (AC) is a digital service in Austria that addresses FCs, their challenges, and needs. This study aimed at evaluating the intended impact of AC and to refine its underlying program theory explaining how the impact comes about.</p> Methods <p>Following a realist approach to evaluation, we considered multiple perspectives and data sources, including four online surveys (S1 <i>n</i> = 52, S2 <i>n</i> = 16, S3 <i>n</i> = 89, S4 <i>n</i> = 169), in-app tracking data, narrative interviews with FCs (<i>n</i> = 8) and two focus group interviews with counselors (<i>n</i> = 10). Quantitative data were analyzed using descriptive statistics, qualitative data were analyzed thematically and interpretatively. A confirmatory approach to theory building was chosen to test and refine the initial program theory.</p> Results <p>The theory on how AC unfolds its impact is presented in two configurational models. FCs can access the digital service anonymously and independently of time and place. In digital counseling, FCs can build a trusting relationship with the counselors and thus receive person-centred counseling. They no longer feel alone with their situation, move on from problems to next steps and exit the counseling room strengthened. AC also has an impact on counselors, especially nursing staff. The counselors are empowered to provide person-centred counseling and can recognize the quality of their actions, make an impact from a distance and see meaning in their actions. They can show what nursing is and can do and thus develop pride in their work and profession.</p> Conclusion <p>AC reveals a way to introduce the concept of person-centredness into a digital context. In this study, we explored counseling as a nursing intervention that takes place anonymously and distantly in digital space – a space in which what they do can be seen.</p>