This paper reports work done in conceptualizing, developing and testing of a mobile phone based graphical user interface (GUI) package targeted at users from the construction industry. System analysis and information design principles were adopted during the development processes. Starting from user requirements based on field studies the development of graphic icons and their testing has been outlined. In addition to integrating individual icons into a GUI, coding and loading the application on a mobile phone has been done to enable testing of the GUI prototype. Users from the construction trade (sample size = 29), randomly selected, were asked to evaluate the designed icons in terms of their acceptance, adaptability and learnability aspects. It was found that learnability of the new GUI was more dependent on age and education level of the user rather than on the length of prior experience they had with mobile phones in general. The length of experience of using mobiles may not be an indicator of learnability in new applications for such user segments due to rapid rise in 'digital literacy' levels amongst semi literate users.