Since the introduction of android operating system (OS) for mobile devices in 2008, smartphones and tablets with rich graphical user interface (GUI) are becoming increasingly popular. Millions of specialized applications are already available for a variety of mobile platforms all over the world. Yet, the complexity of these applications often relies on usability. The wide variety of mobile technologies, platforms, networks and devices presents a challenge when developing efficient strategies to test the usability of mobile applications. The reliable measures of overall usability can be obtained by assessing the effectiveness, efficiency and satisfaction (EES) with which representative users carried out representative tasks in representative environments. However, during the use of mobile applications on the move, user’s cognitive resources were split into handling the application and conducting a primary task, i.e. walking or driving a car. This requires detailed understanding of context where a mobile application is used. Hence, without taking the influence of context in use, it’s not possible to achieve EES. As mobile applications become more complex, specific evaluation frameworks as well as cost effective testing techniques will be essential to assure the development of usable, interactive and high-quality mobile applications. This thesis proposes a conceptual framework for measuring the usability aspect of mobile geo-applications (MGAs) based on adaptation of context in use and runtime user interface (UI) customization. The context-aware UI allows automatic generation of elements of the interface in according with user, task, environment, and device contexts. By combining sensors’ data gathered via mobile devices and user interaction logs, we gain the probability of context in use. This information is then used as a viable source for the decision making of runtime UI customization. Unlike design-time UI specification, runtime UI customization preserve users discomfort when user’s usage status occasionally changed.