Meet the Coder Who Built an App to Warn You When Smart Glasses Are Watching

One winter evening, almost everyone on a packed tram in Munich appeared to be wearing headphones, staring at phones, or peering through dark sunglasses that looked more like tech than eyewear. It’s a minor observation, but those glasses have started to include cameras lately.

This is where the tale of Nearby Glasses, a tiny Android app, starts. Yves Jeanrenaud, the developer of the app, is neither a venture-backed startup founder nor an engineer from Silicon Valley. In his free time, he codes. He is a sociologist by training, teaching, and studying social behavior. In the midst of his late-night programming sessions and academic work, he began to wonder how regular people might be able to tell if they were being recorded by smart glasses.

An app that silently scans your surroundings is the solution, at least for the time being. The rapid integration of wearable cameras into daily life is difficult to ignore. Ten years ago, gadgets like Google Glass caused a great deal of controversy before going out of style. Now companies are trying again, only this time the devices look almost indistinguishable from normal sunglasses.

Certain versions, such as those made through collaborations between Ray-Ban and Meta, have tiny processors, cameras, and microphones concealed inside the frame. Jeanrenaud became increasingly uneasy as he observed the advancement of technology.

There were reports that the glasses were being used in unexpected ways, including secretly filming strangers. Wearable camera footage has occasionally even been featured in investigative reports or social media posts.

He seemed more troubled by that than by the technology. It seems that his response was more about consent than technology. It’s clear that you’re being recorded by a phone. It needs to be held up by someone. But eyewear? They may appear utterly unremarkable.

Jeanrenaud began developing a countermeasure as a result. The way Nearby Glasses operates is surprisingly straightforward. Many wearable devices emit Bluetooth Low Energy signals, which the app continuously looks for. Similar to a digital fingerprint, every manufacturer has a distinct Bluetooth identifier.

The app notifies users when it detects a signal connected to smart glasses made by companies like Meta or Snap. “Smart glasses are probably close by.”

Like a weather update, the alert is displayed on the screen in a quiet manner. However, the meaning can be a little unnerving. While testing the app, it becomes strangely illuminating to stroll through a busy café district. The unseen network of Bluetooth signals that surrounds us is nearly constant and includes phones, headphones, watches, and tablets.

It’s possible that most people don’t give this invisible traffic much thought. Simply put, Jeanrenaud’s app scans that noise for particular signatures.

The system isn’t flawless, of course. The app may generate false positives, even according to the developer. The same alert could be triggered by a virtual reality headset manufactured by the same company. Even if no glasses are actually recording, a nearby device may still be detected.

In the real world, technology rarely acts neatly. However, the app isn’t actually attempting to address every issue. According to Jeanrenaud, it’s more of a signal, a tiny protest against the widespread use of surveillance technology.

He speaks in a remarkably direct manner. He has characterized some wearable cameras as invasive devices that disregard the subjects’ permission to be filmed. Of course, not everyone shares that viewpoint. When creating smart glasses, tech companies frequently highlight privacy features like light recording or audio alerts that let users know when video is being recorded.

However, detractors contend that those cues may be overlooked or misinterpreted. It’s hard to ignore how familiar this debate feels as you watch it play out. Nearly every new recording technology has sparked a similar argument. phones with cameras. Cameras in public areas. Police uniforms with cameras attached.

Every time, society establishes new limits. The invisibility of smart glasses is what sets them apart.

A camera draws more attention than a pair of glasses. It fits in. And maybe that’s why so many people who come across Jeanrenaud’s project online find it compelling. The app is a small side project that many programmers create out of curiosity. But its idea taps into a larger unease surrounding AI-powered wearables and the expanding reach of sensors in everyday life.

Future iterations of smart glasses may even be able to recognize faces or gather contextual data about people in the vicinity, according to some researchers. That possibility hasn’t yet come to pass. However, it is being talked about.

Jeanrenaud appears to be aware that the larger trend cannot be stopped by an Android app. Despite minor acts of resistance, technology tends to advance. He acknowledges the project’s flaws.

Nevertheless, there’s something strangely symbolic about watching the app operate silently in a phone’s background. Surveillance technology has been getting smaller, quieter, and more difficult to spot for years.

Someone has now created software that can detect it once more. It’s unclear if Nearby Glasses will become popular. If time permits, the developer has indicated that the project might be expanded or an iPhone version could be made.

However, the app currently sits silently in GitHub repositories and app stores, scanning Bluetooth signals and listening for microscopic electronic whispers from devices that might or might not be observing.

And that small act of listening says something about the world technology is building around us.