TNPolice CUG is a free Android application developed by Tamil Nadu Police for their personnel. The app serves as a mobile directory of all Tamil Nadu Police Personnel CUG mobile numbers. It allows the police personnel to search for a person using their CUG phone number and also enables them to set up Call Identifier to receive caller notifications if the caller is in the CUG scheme.

To set up the app, police personnel need to enter their CUG phone number and generate an SMS PIN. Once the SMS PIN is received on the CUG SIM, the app automatically detects it and shows a success notification. Police personnel must then enter their rank and choose a city/district or a special unit, or both, to complete the app setup.

The app also has a Groups tab that displays different groups as per the rank setup. The app requires permissions like PROCESS_OUTGOING_CALLS and READ_CALL_LOG for the Caller ID notification feature to work. In case of any technical difficulties, police personnel can contact Technical Services, Tamil Nadu Police.