The rise of the use of mobile technologies in the world, such as smartphones and tablets, connected to mobile networks is changing old habits and creating new ways for the society to access information and interact with computer systems. Thus, traditional information systems are undergoing a process of adaptation to this new computing context. However, it is important to note that the characteristics of this new context are different. There are new features and, thereafter, new possibilities, as well as restrictions that did not exist before. Finally, the systems developed for this environment have different requirements and characteristics than the traditional information systems. For this reason, there is the need to reassess the current knowledge about the processes of planning and building for the development of systems in this new environment. One area in particular that demands such adaptation is software estimation. The estimation processes, in general, are based on characteristics of the systems, trying to quantify the complexity of implementing them. Hence, the main objective of this paper is to present a proposal for an estimation model for mobile applications, as well as discuss the applicability of traditional estimation models for the purpose of developing systems in the context of mobile computing. Hence, the main objective of this paper is to present an effort estimation model for mobile applications.