This paper introduces an Adaptive Context Aware App for the tourism. This app is based on the Context Dimension Tree: a graphical formalism for the context representation through its main components. The system is made available to the user as an adaptive mobile application, which allows a high degree of customization in recommending services and resources according to his/her current position and global profile. A case study applied to Praiano, a town on the Amalfi Coast, has been analyzed considering various users (Italian tourists, foreign tourists ...) and an experimental campaign has been conducted obtaining interesting results