Open source developers have released the source code for an Android privacy tool that found 50% of apps tested were sending personal information to advertising companies.
The tool, dubbed TaintDroid, enables users to track the destination of information sent from their handsets, according to US reports.
TaintDroid is designed to give Android smartphone users greater insight into what their mobile applications are doing.
The team of US computer engineers at Duke University, California that wrote TaintDroid, tested the application using 30 randomly selected Android applications.
They found that 15 sent sensitive information, including the phone's location, to several ad companies' servers.
Two of the apps even shared the mobile phone number and SIM card identifiers with random servers.
The study was a proof-of-concept to show the value of enhancing smartphone platforms to include real-time monitoring tools to give users an awareness of how their information is being shared.