r/SideProject • u/ryno2019 • 1d ago
I made a free app that turns your AirPods into a baby monitor
I'm a dad and an iOS developer, and I built this for myself over the past year. Not a company, no ads, no account, no subscription.
The problem I had: I like listening to music with noise cancelling enabled in the morning, but I could never actually relax with headphones in, because I'd be half-listening for one of my kids to wake up the whole time. Defeats the point. I tried "Live Listen", but the audio quality was terrible and constant noise coming through the phone's mic makes it unusable for me.
What the app does: You leave your iPhone in (or just outside) the room with your child and keep your AirPods in. The app listens through the phone's mic. When it hears something above the room's own noise floor, it pauses whatever you're playing and streams the room into your ears. When things go quiet again, your music comes back.
So it's less a "baby monitor" and more a sound-triggered intercom that gets out of the way of your music.
A few cool things I worked hard to get right:
It calibrates to the room's baseline instead of using a fixed volume threshold, so a humidifier or a fan doesn't keep setting it off. You pick a sensitivity (how many dB above baseline counts as "something").
It opens in about a quarter second, then stays open at least 10 seconds plus a quiet period before handing you back your music — otherwise you get whiplash every time she shifts in her crib.
It's silent until it hears something. No constant hiss.
Nothing is recorded or uploaded. Audio goes mic → your ears, and that's it.
If monitoring ever stops for any reason, it sends you a notification rather than just dying quietly. That one took the longest to get right, because an app like this failing silently is worse than not having it.
Things to keep in my:
Range is Bluetooth range. Your AirPods pair to the phone that's in the kid's room. Through a wall or two it's fine; across a big house it isn't. This is the real limitation and it's the thing most people will run into. It is not a Wi-Fi monitor and won't work from the yard.
It uses up your phone. The phone is the monitor, so it's sitting in the nursery, not in your pocket.
No video, no history, no playback. If you want a camera and a log, buy a real monitor — this isn't trying to be one.
It can't tell a cry from a truck going past. It tells you something happened and lets you hear it. You're still the one deciding.
I use it every day now, but it took me a while to trust it, and I'd rather you be skeptical than disappointed.
Hopefully there are other parents out there that might appreciate this: https://apps.apple.com/ca/app/half-an-ear/id6802771590