App exposes what people call you in their contacts list

Digital Life

Image: CBS News

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

It’s an easy trick we’ve all probably used at least a few times. Adding a descriptive word or two when entering a new contact into your phone can be an easy and effective way to keep track of all those people you don’t communicate with very often — or don’t want to communicate with very often.

Maybe you ran into a college buddy and entered his new number with his nickname from your undergrad days. Or perhaps you took contact info from someone under duress and filled in the last name field with “Don’t Answer.” And maybe that cute girl at the bar got saved as Cute Girl From the Bar.

Once upon a time, this would all be private information. But now there’s Noknok.

Developed in Israel, Noknok grabs the names from the contacts lists of its users, exposing how they’ve labeled people and offering a rare opportunity to see what other people have called you.

“Then you can start a chat with them, but that chat is completely anonymous, and you can ask them for feedback on why they called you a certain name,” explained David Sheetrit, one of the founders of the free app for iOS and Android, speaking from Tel Aviv.

The person who has you in his phone as Annoying Lou knows it’s you messaging, but you don’t know the name-giver’s identity — unless he chooses to tell you.

“The one who’s on the other end has all the power,” Sheetrit continued. “He can block, not participate in the chat, not tell that person who he is, or he can just tell him, ‘I can tell you why I named you like that, but I don’t want to tell you who I am.'”

The app only grabs the contact names from other people who have downloaded it. It uses the same basic permissions as apps such as WhatsApp and Snapchat that also request access to contacts to connect you with other users you already know.

Noknok started in May as a caller ID app that would display the names of callers who weren’t stored in contacts, but Sheetrit and his two co-founders wanted to come up with something more “sensational.” Using information they were already collecting for caller ID, they came up with the “reputation” feature and re-launched on August 7 with that as the sole selling point. A week later they had 60,000 downloads in one day.

Today it boasts 1.3 million users in Israel and is making its first push to build its following in the U.S., which currently stands at about 100,000.

© 2014 CBS Interactive Inc. All Rights Reserved.