M-health has changed the conventional delivery system of health-care, permitting continuous, pervasive Healthcare anywhere, anytime. Chronic disease apps are increasing, as many health workers, patients and clinicians already embracing smartphones in their comprehensive and diverse practices. This paper also mentions the current high end and open challenges in emerging field of smartphone-based healthcare applications. One of the M-health’s biggest fears and technical barriers is the security and privacy of the personal information. While the usability testing and evaluations of chronic disease apps have not yet touched the accuracy level of other web-based applications. This study is being conducted to learn about challenges of m-health apps and to identify the factors that affect the usability of such applications.