There's an App for Bust Some Ghosts: Using a K2 milliGauss Meter 2

The K2 meter is soundless, making it great for ghost hunting investigations where unnecessary noise is a distraction, and silence is a top priority. Versions of one of the leading apps, Ghost Radar, have been downloaded more than six million times, says Jack Jones, who created it. "People are really interested in paranormal activity but can't afford to buy the K-II," Mr. Jones says. "I can throw something out there for a buck. There's a market for this."
The difference between a K2 meter and a standard EMF detector is that the EMF detector uses a needle to indicate the presence of energy (when the needle jumps up between 2.0 and 7.0, it is indicative of a nearby energy source) whereas the K2 uses a series of LED lights (green-yellow-orange-red.) Unless you choose to lower the volume, a regular EMF detector will beep when turned on or when it detects a change in frequency. Keith Tupper, the inventor of the K-II meter, calls it silly to use a smartphone as a sensor for electromagnetic fields, especially if the phone is periodically pinging a tower or receiving email or text messages.

"A phone is just spewing this stuff," Mr. Tupper says. "You'll say, 'Oh my God, there's a ghost,' but no, it's a phone in your pocket."

Mr. Tupper questions the claims of many of the ghostly apps, arguing the K-II meter is a reliable instrument. "Does Casper exist? I don't know," he says. "But if this instrument says there's an electromagnetic field, there's a field."

Michael Weber, who developed Ghost Hunter M2 with his twin brother, David, says the app compensates for an iPhone or iPad's known level of electromagnetic activity. It measures EMF about as well as the K-II but performs many more functions, he says. "The smartphone has really accelerated the field of paranormal investigation," he says.

In the digital dustup, purists prefer to collect data with widely accepted engineering tools to better convince a skeptical public.

YouTubers test out Ghost Radar, one of the most popular mobile apps for detecting "ghosts." WSJ's Andy Jordan samples the online amateur reviews.

Other ghostbusters say the digital applications have the potential to open new avenues for tracking spirits, which many believe manipulate energy to communicate since they no longer have traditional voices.
Mr. House, an ex-cop and current Transportation Security Administration night supervisor at the Raleigh-Durham International Airport, says the new technology can yield exciting albeit cryptic results. "People told the Wright brothers they were crazy," Mr. House says. "They had to go out and show it could be done."

Mr. Coffey says he's convinced that the apps are picking up something. "My assistant was on Ghost Radar and her Ghost Radar said, 'Smile.' I said, 'will you come to us and make an appearance?' And her Ghost Radar said 'appearance.' "

Ms. Ray, the veteran Kansas City investigator, recently led a Haunted House tour for the Chamber of Commerce in Atchison, Kan., and let a few people run their apps despite her doubts. The experience failed to convince her.

"They're like, 'Ooh, it just said dead right now.' Really? You know it's just random, right?" she says.

D.J. Grothe, president of the James Randi Educational Foundation in Los Angeles, which promotes critical thinking, likens ghostly apps to tea leaves. "Just five years ago, ghost hunters were the silly goofballs trying to spook themselves with a night camera," Mr. Grothe says. "Now they're the old fuddy-duddies who are trying to keep the status quo."