Up-to-date web (2.0) is collaborative, mobile and contextual. It takes into account human actors as well as different things, i.e. LBS (location based services) and internet of things are now an integral part of internet. We are working on this approach with the acronym MOCOCO (Mobility, Contextualization, Collaboration). Our research work is generic with multiple applications in working, learning and societal situations. Professional and home working situations, professional and teenager contextual mobile learning situations as well as Smart City applications are taken into account: transportation, goods distribution and local sport and cultural activities. In the paper we propose to present our approach for contextual mobile user interfaces and their application to the Smart City.