Pry-Fi is an Android app to stop advertisers from using your smartphone Wifi connection to track your movements. This app does not need you to switch off your Wifi, which is the only other way to accomplish this. Pry-Fi blocks broadcasting to Wifi networks while scanning in the background allowing you to connect to the network and randomizing your phone’s MAC address making you to appear unique to each access point.
Your phone’s MAC address, used by advertisers to track down your movements as you hop Wifi access points, will never be used twice to different networks. This privacy app will show your real MAC address on the screen for your own information and the random or wanted MAC address assigned to you by Pry-Fi visible to public access points.
Another Pry-Fi option called “Go to war!“, emulates dozen of smartphone MAC addresses poisoning the trackers database by listing the same MAC address in two different locations at the same time. This is an effective way to subvert trackers data mining, although this mode will quickly drain your battery life.
Smartphone Wifi tracking is not something out of science fiction. A few high street stores are already using it to find out how many people go inside the store, what path they walk, the stops they make and if they finally buy something or not. The stores can correlate Wifi movements with CCTV surveillance, the fantastic benefit of tracking people with their own smartphone Wifi connection is that, unlike CCTV, Wifi tracking can be used for mass surveillance with little effort, in CCTV you need to manually pinpoint each target.
Bear in mind that according to NSA documents leaked by Snowden spy agencies use cell towers to track people’s movements. Pry-Fi will protect you from advertisers but most likely not from spy agencies with access to the whole mobile phone network.
Note: This is a proof of concept app that needs a rooted device