Mobile applications (apps) have attracted increasing attention as an unprecedented opportunity for retailers. This study aims to explore how a branded app supports customers’ shopping decision during the COVID-19 (coronavirus) crisis. Integrating person-environment fit theory and the theory of exploitation and exploration, this study links person-app fit and person-brand fit to explorative use and exploitative use of a branded app, which both contribute to customer decision performance. Perceived fluency toward cross-channel integration positively moderates the fit-use linkages. Data obtained from 835 app users verify all of the proposed hypotheses. Results indicate that customers with different fits (person-app fit and person-brand fit) hold different thoughts toward their exploitative use and explorative use, which add equal value to support their decision making. Useful theoretical and practical implications are also provided for researchers and marketers interested in this area.