SentinelSmart doorbell
A smart doorbell for any gate

Someone's at the gate.Your phone rings.

Turn a QR code on your gate into a doorbell. Visitors scan, smile and ring. You see who it is, tell them you're coming, or talk to them live, wherever you are.

See how it works
  • No app for visitors
  • Location never stored
  • Passkeys & 2-step sign-in
How it works

Scan. Smile. Ring.

Three taps for the visitor, one decision for you.

  1. 01

    Scan

    A QR code at your gate opens a page in the visitor's browser. No app, no sign-up, no ads.

  2. 02

    Smile

    They confirm they're really at your gate, smile for a quick photo and ring. Everything else is optional.

  3. 03

    Answer

    Your phone rings like an incoming call, with their photo. Tell them you're coming, send a message, or talk live.

Features

Built for real gates.

Calm, private and hard to abuse.

Only from the gate

Each QR is tied to your gate's location and radius. A screenshot can't ring your bell from across town.

A face with every ring

See who is there before you answer. No photo? The ring still goes through, marked clearly. Every ring is kept in your history.

Talk from anywhere

Two-way audio over a relay that works across Wi-Fi and mobile data. Your own camera never turns on.

Every door, one app

A QR for the front gate, the back door and the garage, each with its own colour and rules.

Quiet when you want it

Quiet hours per door. Rings still arrive, silently, and visitors are told you'll see it later.

Your fingerprint is the key

Passkeys, an authenticator app for a second step, and recovery codes for emergencies.

Private by design

Your door, your data.

A doorbell sees people. We keep only what's needed, for as short a time as possible.

0
location points stored
Checked once, then discarded
30
days at most for photos
Deleted automatically, sooner if you choose
1
tap to replace a QR code
If it's ever shared or misused
18+
adults only
No ads for visitors, ever

Visitors are never forced to share a name or a reason. Read the privacy policy

FAQ

Good to know.

Short answers to the questions people ask first.

Do visitors have to install anything?

No. They scan the QR code with their phone's camera and a page opens in the browser. They allow location and camera once, take a photo, and ring.

What stops someone ringing from far away?

The doorbell checks the visitor is within the radius you set (75 m by default) using their phone's location, and the reading has to be fresh. A screenshot of your QR code can't ring your bell from across town, and you can replace the code in one tap.

What happens to the photo and the location?

The photo goes only to you and is deleted automatically after 30 days. The visitor's location is used for that one check and then thrown away: it is never stored.

Can I talk to the visitor?

Yes. Tap “I'm coming” to tell them you're on the way, send a quick message such as “I'm away right now”, or tap “Talk to them” for live audio. Your own camera is never turned on.

Does it work when I'm not home?

Yes. Rings reach your phone anywhere, and talking works across Wi-Fi and mobile data through a relay server.

Is it free?

The app is free and supported by ads shown only inside your own app. Visitors never see ads, and no ad ever appears during a ring or a call.

Which phones does it work on?

The owner's app is for Android (coming soon on Google Play). Visitors can use any phone with a camera and a modern browser.

Put a doorbell on your gate.

Print the poster, put it up, and never miss a visitor again.

Printing your QR code