Since signing a deal in December with Internet telephony giant Skype, the company's server has crashed five times after tens of thousands of web users rushed to download the lie detector, offered for free.
"This is a really neat application, and the kind of thing we want to see more of," said a statement from Paul Amery, director of the Skype Developer programme.
The six employees of BATM subsidiary KishKish in Israel and Bulgaria, developed the add-on, which has an interface resembling a real polygraph, complete with monitors and needles.
The lie detector monitors in real time the stress levels in a speaker's voice. "In the end, the voice is the biggest manifesto of what we think," said Marom.
A user of the Internet lie detector needs to talk for 15 seconds to calibrate his or her voice, then sound waves start to peak if stress levels are high, a light flashes from green to red and a needle jumps to the end of a scale.
Employees spend hours responding to emails and forums from thousands of users across the world, and they brush off criticism on their web forum from people having trouble using the tool.
"If you just make something up for the sake of it, it won't work because you won't be stressed," explained Alex Rosenbaum, 35, head of development at KishKish.
The company said it tested the tool on an insurance company that reported it was more than 90 percent accurate. It also said it had requests from police services to adapt the software, and even offers from former Russian spies to help develop it.
KishKish sees the project as a further attempt to stretch the possibilities of Internet communications, and for now - like many Internet start-ups - it offers the product for free.
Workers at the small office, in a landscape of palm tree-lined roads, shopping malls and beachside apartments, spend many hours playing with ideas for a range of new products.
The next one they plan to release is a "Love-o-meter", designed to detect emotional interest levels across the web. "They'll like it in France," Marom predicted.