Research on mobile health (mHealth) applications has investigated how such technologies contribute to a responsibilisation of users/patients. This literature largely focuses on the individual responsibilities constructed by the apps and the neoliberal environments that enable the positioning of the user as responsible. With this focus, this scholarship is less attentive to the role of social relations in responsibilisation. In this article, I demonstrate how relational responsibilities are constructed in the communication of a North American self-testing app for “early changes in (...) cognition”. Through an analysis of qualitative expert interviews and images on the app’s web presence, I show how social relations are, in fact, mobilised in the construction of the responsibilities to support the user in the test situation, to take the test for the sake of others, and to make others take the test. Based on this analysis, I argue that the role of social relations should receive more attention in the literature on responsibilisation, because they lead to additional, sometimes gendered responsibilities that a focus on individual responsibilities would miss. (shrink)