Despite their ubiquity the network behavior of mobile apps remains notoriously opaque. This opacity stems from permission systems employed by mobile OSes to keep users safe from malicious apps.
Available on the Play Store, Lumen (formerly known as ICSI Haystack) is a mobile measurement platform developed in collaboration with researchers at ICSI, that reveals the network level behavior of mobile apps by making novel use of the VPN permission on Android. Using this system we are able to characterize mobile traffic and detect privacy leaks in mobile applications.
You can visit the project website for more information.