Today millions of mobile apps are downloaded and used all over the world. Guidelines and best practices on how to design and develop mobile apps are being periodically released, mainly by mobile platform vendors and researchers. They cover different concerns, and refer to different technical and non-technical stakeholders. Still, mobile applications are developed with ad-hoc development processes, and on-paper best practices. In this paper we discuss a multi-view modelling framework supporting the collaborative design and development of mobile apps. The proposed framework embraces the Model-Driven Engineering methodology. This paper provides an overall view of the modelling framework in terms of its main stakeholders, viewpoints, and modelling languages.