Today the number of phones in the world are more than five billion. In the last generation of phone there are a subset called smartphone, the use of this subset is growing. These devices are more and more sophisticated, capable of measuring many parameters from environment. In order to do that this smartphone is equipped with a several sensors and by means of an application (APP) that pick up the information from each sensor, it is possible to send, share, analyze, and display the measured data. Nevertheless, people could use this data without real information on accuracy of measured parameters. Thanks to these devices in the next few years there will be the opportunity to have a big wireless sensor network. With this paper the authors try to tackle the uncertainty question related to sensors suited to smart phone or any other android devices. The main goal has been to address this new idea implementing the first application that analyze a method of calibration with the aim of evaluating the uncertainty of sensors data. © 2013 IEEE.