In short, supervisors create visual maps of workers' days.
State officials say the GPS surveillance of remote workers, such as fire and housing inspectors, helps in responding to emergencies and improving productivity.
Workers' advocates counter that this new frontier in workplace monitoring can sap morale and engender resentment toward employers.
"The public is much better off with caseworkers, supervisors looking at their reports instead of following their movements all day long," said Lew Maltby, president of the nonprofit National Workrights Institute in Princeton.
"It pulls supervisors into the wrong sort of employee evaluation," he said. "Does it really matter if the guy stops at 7-Eleven for a Coke during the course of the day? Not really."
Verizon Wireless rolled out the Field Force Manager app in 2006, said Steve Witting, the company's director of data sales for the Philadelphia region. Businesses of all sizes across the country are using it, he said.
Customers have reduced their insurance rates by monitoring vehicles, he said, and boosted morale by awarding bonuses to productive workers.
"You're going to have those individuals that want no part because they think Big Brother is watching," Witting said. "But my experience is that's not the case."
