Technological growth has been exponential in relation to mobile devices (such as embedded sensors) that have allowed developing context-aware mobile applications for the market. This growth generates a new challenge about how to develop this kind of application to adapt them to the current user’s demand. Nowadays, there are several approaches that could be used to create context-aware mobile applications, but these approaches are designed without considering to provide variability in the kind of generated applications. The aim of this paper is to propose a building tool that has been designed from scratch taking into account variability points in order to generate a wide variety of contextaware mobile applications. The first version of our tool is presented in this paper which is based on UML tools like Eclipse, Sirius Obeo, and JBoss. Finally, a discussion of different aspects is detailed to help designers to have guidelines to select the appropriate development environment for the design of building tools for context-aware mobile applications.