An app called Scanner Buddy allows people to search by state, find local cities and counties, then keep an ear on police. No need to buy scanner radios.
Officers in one Florida Police Department say they're worried criminals could get a head start on them.
"They could quite literally hear us en route setting up a perimeter and know when they need to leave," said Travis Carraway with the Lake Mary Police Department.
The manufacturer of the scanner app points out it's illegal to listen to a scanner while committing a crime in some states.