People travelling by public transportation benefit from information such as stop times, relevant bus routes and current disturbances. It allows people to streamline their travel and not to be left standing in a bus shelter with the rain as sound backdrop. A natural way to get information today is through your mobile device. For a public transport operator, it is therefore important to provide a mobile application with functionality for this purpose. It is also important that the mobile application has usability, otherwise it does not benefit the individual. In many development projects, the focus is on functionality and other types of requirements, such as usability, are often discovered relatively late.The aim of this paper was to design a new user interface and examine which design guidelines and principles that are useful in the development of mobile applications for public transport. Using the theory of usability, design guidelines and principles, other mobile applications with the same purpose as well as the users themselves, we could develop a prototype of a user interface for a public transportation application with increased usability.