Information and communication technologies are today an integral part of our life, and digital technology is constantly finding its way to new application areas. With a higher level of integration and specialisation of digital services, the complexity of systems rises. This complexity can be managed by careful design, where the concept idea and the application usability are validated with users and tested in an authentic use context. User-centric design (UCD) focuses on addressing the target user’s needs and preferences by involving users in the design process. In-the-wild studies offer an opportunity to test the research prototypes in real-world use contexts and provide valuable feedback on the feasibility and usability of design solutions. In this chapter, we present two case studies on mobile and ubiquitous technologies trialled in the wild and discuss the specific requirements arising from those trials.