Nowadays, smartphones are an indispensable part of most people's lives, they are a means of enabling communication and exchange that makes everyone comes together. However, it comes with a cost as the production and use of these systems is affecting the global earth ecosystem. Considerations about sustainability are more and more in people minds and the possibility to offer sustainable smartphone applications can be an asset to any company. We propose in this work a sustainability matrix for Smartphone in order to identify their sustainability degree and offer some new thinking to their developers. We created this matrix with a state of the art study, expert interviews and a public questionnaire. We evaluate our matrix on an application and discuss the results with its development project manager.