The US Department of Homeland Security enlisted smartphone users in its fight against child pornography Thursday with an iPhone app intended to make it easy to report suspected child predators.

The Operation Predator app lets informants submit information via email or a telephone tipline, and also includes a run-down of the nation’s most-wanted alleged child sex offenders.

It is free to download via iTunes — albeit with a warning that it is not for persons under the age of 17, presumably the group most vulnerable to child sex crimes.

“When children are being sexually abused and exploited, it’s a race against the clock to rescue the child and bring the predator to justice,” said John Sandweg, acting director of US Immigration and Customs Enforcement (ICE), the Homeland Security unit behind the app.

“These investigations are one of our highest priorities and, in today’s world, we need to be technologically savvy and innovative in our approach,” he said.

Topping the app’s list of nine fugitive suspects was one “John Doe,” a white male aged 45 to 55, “wanted for production of child pornography,” who could be living “anywhere in the world.”

ICE said the unidentified man appears in glasses and a beard in video files seen by ICE agents in Los Angeles earlier this year sexually abusing a girl aged between 10 and 12 in a wood-panelled room.

Other suspects — all wanted for making, distributing or owning child pornography — include a 35-year-old Indian national who allegedly helped run an Internet bulletin board for child-porn purveyors.

The Federal Bureau of Investigation (FBI) has for some time offered a broadly similar app that features not only America’s 10 most wanted criminals and terrorists, but also a list of missing children.

ICE said its app would be available for non-Apple devices “in the near future.”