Resumen: During the Covid-19 pandemic, contact-tracing apps have offered effective help to bend the contagion curve. Thus, it is of critical importance to understand the factors that influence contact-tracing apps’ adoption among citizens. In particular, the successful adoption and usage of contact-tracing apps strongly relies on individual motives. Therefore, this study draws on the theory of altruistic and egoistic motivation for prosocial behaviours to analyse the underlying motives through which citizens engage in voluntary behaviours aimed at using and promoting the use of contact-tracing apps. The study also examines the mediating role of users’ trust in the app. Data from 221 users of Ireland’s Covid Tracker app was analysed. Structural equation modelling with PLS was used to test the research model. Findings show differences between egoistic and altruistic motivation in promoting app use and sharing. Egoistic motivation significantly promotes voluntary behaviours among citizens and users’ trust in the app mediates this influence. Yet, contrary to predictions, in the context of the pandemic, altruistic motivation does not play a significant role in engaging citizens in these voluntary behaviours, either directly or indirectly. The findings of this study are important for policy makers and may inform future policy decisions regarding the implementation of contact-tracing apps in the case of new pandemics or for other contexts requiring cooperative daily check-in. Idioma: Inglés DOI: 10.5295/cdg.232047sc Año: 2023 Publicado en: Cuadernos de Gestion (2023), 1-14 ISSN: 1131-6837 Factor impacto CITESCORE: 3.0 - Economics, Econometrics and Finance (miscellaneous) (Q2) - Industrial Relations (Q2) - Business and International Management (Q2) - Business, Management and Accounting (miscellaneous) (Q2) - Finance (Q2) - Organizational Behavior and Human Resource Management (Q3) - Strategy and Management (Q3) - Marketing (Q3)