I work from coffee shops and co-working spaces regularly, and I’ve always had this nagging worry when I step away to use the restroom or grab another coffee. Sure, I take my phone and wallet, but my MacBook is still sitting there with all my work. I recently discovered Rex, and it addresses this specific anxiety in a way that feels practical rather than paranoid.
Rex is a menu bar app that automatically arms itself when your MacBook is in a potentially vulnerable location. The core concept is straightforward: if someone tries to pick up your laptop and walk away with it, Rex sounds a loud alarm through your Mac’s speakers. The alarm plays even if you have headphones plugged in, which solves the obvious workaround that would make most alarm apps useless. It simultaneously sends the alarm to any connected wireless headphones, so you’ll hear it even if you’re not at the table.
What makes Rex different from other laptop alarm apps I’ve tried is the always-armed approach. Most alarm apps require you to manually arm them each time you step away, which I consistently forget to do. Rex handles this automatically, learning your patterns and arming itself when appropriate. The developer emphasizes that this makes it seamlessly integrate into your workflow rather than becoming another thing to remember.
The app includes push notifications to your iPhone or Android device, and it supports Telegram integration if that’s your preferred notification method. There’s also a motion detection feature coming soon that will monitor MacBook movement and trigger alarms if the device is being moved unexpectedly.
Privacy is a clear priority here. Rex doesn’t require any cloud accounts, includes no analytics SDKs or ad tracking, and collects no data from your device. The only information that leaves your Mac is the notifications you choose to enable and any optional webhooks you configure. This privacy-first approach is reassuring for a security app that has system-level access.
Rex is available on the Mac App Store for $4.99. The developer, Sixcolors Apps, positioned this as a trustworthy alternative to competing anti-theft tools that can feel unreliable or sketchy. During my testing over the past two weeks on my MacBook Air, the app has been stable with minimal system impact, though I haven’t tested the actual alarm in a real theft scenario since I’d rather not cause a scene at my local cafe.
The app works best for people who regularly work in public spaces where laptop theft is a genuine concern, like airports, cafes, libraries, or shared office environments. If you primarily work from home or in secure office spaces, Rex probably isn’t necessary. But for anyone who experiences that moment of anxiety when leaving their MacBook unattended in public, Rex provides a layer of protection that feels both practical and unintrusive.
