ABSTRACT Background and Aims Patient adherence plays a crucial role in effective chronic disease management. eHealth interventions utilizing smartphone applications (apps) are emerging as a promising approach to support adherence. This study aims to explore the acceptability, usability, perceived benefits, and barriers by app users, both with or without chronic diseases. Methods In‐depth interviews were conducted with 12 Cantonese‐speaking patients aged 40 years or above who were eHealth app users. Participants' perceptions of the app, their preferences, and the impact on health outcomes were analyzed using the Consolidated Framework for Implementation Research (CFIR). Results Participants had positive perceptions and understanding of the app, with a majority preferring “My eDrug Manager” over other similar apps. Monitoring medication and blood pressure improved user habits, while medication details and various reminder styles enhanced patient adherence. However, participants emphasized the need for efficient technical improvements and timely customer support. Some users found the app incompatible for disabled patients, while others desired comprehensive, customizable features adaptable to individual needs. Varying levels of interactivity required by users had the potential to negatively impact their perceptions of the app. Conclusion This study provides insights into the benefits and concerns regarding user intention to adopt the eHealth app. Participants suggested improvements for different reminder styles and comprehensive health reports. Findings can inform policy makers about the current situation and how implementing user feedback could increase app usage, medication adherence, and ultimately improve individual health outcomes. Clinical Registration: Not applicable.