Mobile health (mHealth) apps have fundamentally changed the usage of smartphones in people's daily lives. In this context, sleep apps, the most popular mHealth apps, can track and enhance user well-being. Understanding the antecedents of the usage of sleep apps is of timely research interest. This study focuses on whether and how sleep apps influence Generation Z users’ well-being (as this generation represents a promising market segment for smart devices). More precisely, the authors enhance the technology acceptance model with the uses and gratifications theory, and they test the perceptions of a sleep app before and after use. Structural equation modeling shows that the sleep app positively influences perceived usefulness, perceived ease of use, intention to use, real usage, and perceived well-being. Consumers rate higher levels of well-being and usefulness regarding the sleep app before use than after use. Perceived usefulness can enhance usage and, in turn, well-being. Privacy concerns and personality traits moderate the direct effects on well-being. Health app managers should understand the importance of the utilitarian benefits of disruptive technologies, which can be enhanced through empowerment (i.e., self-tracking, self-knowledge, and self-management) and well-being benefits. However, privacy concerns remain the primary reason for consumers’ reluctance toward mHealth apps.