Abstract: The aim of this paper is to present the design stages of a built-for-purpose disaster response mobile application called iAwhina. The authors propose to design iAwhina as an interactive user-friendly offline mobile application that provides flawless user experience to support and aid in emergency response situations. The prototype works in both online and offline modes, using ad hoc network technology. The design process followed during the development of the user interface is based on a set of usability criteria that are presented in this paper. A systematic literature review on the usability criteria for disaster mobile applications and discussions with industry experts helped to finalize the user interface elements that will enhance the usability of the application. The relevant features that will be included in the application were drawn from literature. A discussion on how the design process plays a critical role in designing disaster mobile applications is also presented.