Our smartphones know everything about us – who our friends are, where we have been, our financial details, our health information and other intimate details of our lives. But can we trust our phones to keep these our personal information secret?One of the biggest security and privacy challenges of smartphones are the very apps we install on them and use every day. Many applications that we install are free, everything from utilities to games; however, if we are not paying for these apps, how are the developers making money?Many app developers generate revenue by harvesting information from your device and selling this aggregated information to marketers and other organizations. Often times, what these applications collect is disclosed in privacy policies and terms and conditions – yet most of the time they don’t.Furthermore, many app developers may incorporate third-party tools and libraries in their apps, which harvest additional information the developers may not be aware of.I am an advisor to a startup in Portland called Privacy Sentry, focused on unveiling the secret behavior of mobile applications. Their first app for Android, called SpyAware Privacy Defender, provides device owners the ability to see what data is being collected from their device, as well as where that information is being sent to. In addition to the app itself, additional tools are deployed to provide a deeper analysis of an applications behavior at the packet level.