It is no surprise, given smartphones convenience and utility, to see their wide adoption worldwide. Smartphones are naturally gathering a lot of personal information as the user communicates, browses the web and runs various Apps. But they are equipped with GPS, NFC and digital camera facilities, which means that smartphones also generate new personal information. And since they are almost always connected to the Internet, and are barely turned off, they can potentially reveal a lot of information about the activities of their owners. The close arrival of smart-watches and smart-glasses will just increase the amount of personal information available and the privacy leakage risks. This talk introduces the Mobilitics project that is currently conducted by Inria/Privatics and CNIL, the French data protection authority. After an introduction to the problem and the motivations behind tracking techniques, we will detail the logging and analysis tools we developed for the iOS and Android Mobile OSes, and some of our findings. It appears that the actual behavior of certain Apps running on our smartphone may be much more intrusive than what we think, and sometimes what is written in the legal notice. A cleanup of some practices in terms of personal information collection is needed.