Peeple sends you mobile notifications when someone knocks or opens the door.

Hundreds of years ago, a breakthrough in door design enabled people to see who was at their front step without the risk and inconvenience of actually opening the wooden portal. When someone wanted to look out, they simply glanced through the tiny door to take a peek. (Think Wizard of Oz.) Fast forward several years, that hole not only shrunk down in size but became outfitted with a fisheye lens to allow for a one-way, wider field of view of visitors. This innovation, which is commonly known as a “peephole,” first debuted in an issue of Popular Science in the 1950s and would remain unchanged for decades.

With countless connected doorbells and locks already on the market, it was only a matter of time before someone devised the idea of a smart peephole. Created by Austin-based entrepreneurs and graduates of the Highway1 accelerator, Peeple is a disc-shaped gadget that attaches to the inside of one’s door, captures a live video and sends it to an owner’s smartphone whenever someone knocks. This way, whether a user is home or away, they can easily monitor visitors coming and going.

The system consists of a circular box housing a camera, an accelerometer, a battery and a wireless chipset that mounts to an existing peephole or affixes to the glass paneling of a door. Peeple works by connecting to an in-home Wi-Fi network and then transmitting a mobile notification whenever someone approaches the door. An embedded sensor detects vibrations from a visitor’s knuckles, which triggers the device to record a live feed and wirelessly relay those images and its timestamp to Peeple’s servers. From there, a user receives a push notification on their smartphone via its accompanying app (available in both iOS and Android).

What’s more, Peeple is activated if the door opens. This means users will be alerted if an uninvited guest has entered their home, a child or an elderly family member has let themselves out, or if an intruder has broken in. There is also a history of all knocks and openings.

For those who have ever wondered how many people come by when they’re not home, now they’ll know. Whether it’s securing the premises, keeping tabs on housecleaners or tracking UPS deliveries, this modern-day solution gives users the ability to screen their doors in the way that they screen their incoming calls with caller ID. Not to mention, since it only wakes up when someone is knocking, Peeple has a battery life of up to six months on a single charge.

Looking for an IoT savvy accessory for your front door? Take a peek at Peeple’s Kickstarter page, where the team is currently seeking $50,000. Shipment is expected to begin in May 2016.