the development of context-aware software applications. Furthermore, mobile devices often operate in changing contexts as device users move around in their daily lives. This creates both the opportunity and the need for context-aware mobile applications to
improve their services and add unique values by making use of contextual information. As a simple example, if a phone can automatically display contents vertically or horizontally, depending on how its user holds the phone, it brings convenience to its user. While this is straightforward to implement with the presence of the gyro, and requires no user training, it is an important step forward because previously, functions like this required explicit user input and were not automated. Such functions were therefore often reluctantly or infrequently used. Thus, well-design context-aware
m-health applications could speed up adoption of certain m-health features and improve both end user experience and acceptance of certain things that are good for health but not easy to keep up with, such as keeping a diary of the number of steps walked every day, or a headache dairy.