Mobile systems and mobile applications have gained a lot of attention both in research and industry over the last years. The market share of mobile devices is constantly growing. More and more users expect their mobile devices to provide functionality similar to the one they know from their desktop computers, but also to provide additional, mobile device specific functionality, like location based services. However, software development for mobile devices is still cumbersome and a methodology geared towards supporting the development of such mobile applications is still lacking. While there is broad agreement that developing for mobile devices is more difficult than traditional software engineering, we lack a precise understanding that goes beyond anecdotal evidence of why this is the case and how the situation can be improved. We do not precisely know where and how the development of mobile application differs from “normal” software development and where new methodologies are needed. Aspects that need to be addressed in this context are, among others, the questions of software architectures for mobile applications, approaches to the software design for mobile applications and how the consequences of being mobile; for example, changing location, changing context, changing connectivity, heterogeneous software and platforms influencing the software development process, and what design approaches reflect the specialties of mobile applications and systems appropriately. At the same time, application development platforms we see today are getting more powerful everyday, with an ever growing list of funky features, bells and whistles. The downside to this is that development environments are themselves getting more complex and more difficult to master.