Vigilo

Vigilo turns any device with a camera into a motion-detecting security camera, without an app store or an account. The official distribution is the hosted web app at vigilo.eifr.dev: open it on the old phone, allow camera access, prop it up facing the door - that is the whole setup. It is a progressive web app, so you can install it to the home screen from the browser, where it behaves like a native app. And because the code is MIT licensed, the source is also downloadable from GitHub and buildable with Bun (Preact + Vite) if you would rather self-host it.

The video feed is processed locally on the device and never streamed anywhere; settings live in browser storage, and there is no cloud account holding your footage. Detection comes in two flavors. The default is an EfficientDet-Lite AI model running in the browser, preferring your GPU with an automatic CPU fallback, with person tracking on by default and a tunable confidence threshold. A lighter pixel-motion mode built on OpenCV.js suits older hardware, and a test mode lets you upload any image to watch detection work before trusting it with your hallway. Low Light Vision fires the phone's flashlight, or lights up the screen at full brightness, when movement happens in the dark - so the snapshot actually shows something.

Alerts are opt-in and arrive through your own free Telegram bot: each motion event lands in your chat with a snapshot - the one thing that leaves the device, and only if you enable it. A debounce keeps pets from spamming you, and you can reply to an alert to start or stop tracking an object type, or send 'status' for a health check. If the internet drops, alerts queue locally and send when the connection returns. Honest limits: the browser tab must stay open and the phone awake, so plan on keeping it plugged in, and it captures snapshots on motion rather than continuous video.

Our article covers the details: https://www.freewares.org/blog/vigilo-old-phone-security-camera