SPIDEY is an app that helps you identify whether someone is attempting to monitor your cell phone location or activity. The app detects fake cell phone towers (called IMSI-catchers) and informs you if there’s a potential threat to your cell phone privacy. IMSI-catchers mimic real cell phone towers, acting as a middleman between mobile phones and cell companies, allowing adversaries to receive potentially private information from you mobile phone and to identify you and your location. While the app doesn’t provide a method for stopping this surveillance activity, it alerts you to potential anomalies in your cell networks, and gives you practical tips about what to do if you think someone is trying to spy on your phone.

Both law enforcement agencies and criminals use IMSI-catchers. The FBI or local police might deploy the device at a protest to obtain a record of everyone who attended with a cell phone. Identity thieves might sit with an IMSI-catcher in a parkedcar in a residential neighborhood, stealing passwords or credit card information from people nearby who make purchases on their phones. There are powerful, expensive IMSI-catchers in use at federal agencies and some police departments. At the same time, people with the right technical skills can build smaller devices for just a few thousand dollars.

IMSI-Catchers can allow adversaries to intercept your conversations, text messages, and data. Police can also use them to determine your location, or to find out who is in a given geographic area at what time. All of this surveillance happens in secret. Unless you use Spidey, there’s no way to tell whether your cell phone is connecting to a regular cell phone tower or to a tricky IMSI-catcher device. Protect your private data and start scanning your area.

• [√] Detect active cell towers in area, and keep track of changes
• [√] Receive live updates for changes in tower number and location
• [√] Steps for what to do if an anomaly is detected
• [√] Privately share data with Spidey Help Desk (optional)
• [√] Alert your social networks to your scan results (optional)