This chapter describes some conceptual and practical issues in the development of a professional mobile learning system. The main focus of the chapter is the implementation of a mobile learning solution for the requirements of a specific working environment. The study proposes a conceptual framework for mobile learning applications, based on multiple studies of mobile learning design requirements, and uses it as a design tool for the development of the new system based on situated learning in the workplace. This approach is illustrated through the development life cycle of a prototype mobile learning solution. Finally, the chapter reviews and evaluates the success of the prototype and the utility of the framework as a design tool, identifies potential issues and outlines ideas for further development and research.