Mobile applications (apps) cover a large variety of domains; people spend more time daily on apps to manage their jobs. A significant reason for app success is its unique characteristics, which can be attributed to app design and its content features. However, there is less evidence and guidelines to show how app design and its content features affect continuance intention. In this empirical study, we use the perspective of IS effectiveness to evaluate relative factors. We grouped three quality variables to influence intimacy and continuance intention: design quality, information quality, and service quality. The IS success model has been proposed to explain the effect of user behavior on mobile apps. Our findings suggest that design quality, information quality, and service quality impact intimacy, which in turn affects continuance intention. The findings imply that providing design quality and enhancing intimacy is the key to app success.