Phone Guardian: Left-Behind
Alert the moment you leave it
$1.99 · Designed for iPhone. Not verified for macOS.
The instant your iPhone leaves your Apple Watch, your wrist buzzes — faster than Find My. Safe Zones and watch-face mode included. One-time purchase, no ads.
"Wait — where's my phone?" Let's make that heart-drop moment a thing of the past.
Phone Guardian buzzes your Apple Watch the instant the Bluetooth link to your iPhone breaks. Find My helps you locate a phone after it's lost — Phone Guardian tells you the second you leave it, so you can just turn around.
■ Perfect for moments like these
- Heading out: know the second you leave your phone at the door
- Cafés & restaurants: never leave it on the table when you get up
- Travel & trips: avoid leaving it at hotels or airports
- Trains & buses: get alerted the moment you leave it on your seat
■ Key features
- Instant left-behind alert: your Watch buzzes within seconds
- Distance warning: a gentle heads-up before the connection is even lost
- False-alarm guard: a brief blip won't trigger it (0–10s grace)
- Safe Zones: silence alerts at home or any place you choose
- Ring your iPhone: find it loudly from your Watch, even in silent mode
- Also a watch face: turn the monitoring screen into a digital or analog clock, with your own photo background, world clock, and corner widgets
- Japanese / English: switch anytime inside the app
■ Battery friendly
Only low-energy Bluetooth and near-zero-power geofencing. No constant GPS — battery impact is minimal.
■ Privacy
No location, no analytics, nothing leaves your device. Everything stays local.
■ Before you start
- Requires an iPhone on iOS 17+ paired with an Apple Watch on watchOS 9+
- One-time purchase. No subscription, no ads.
- Due to watchOS rules, alerts can be delayed on some models or usage patterns. If that happens, keeping Phone Guardian as your Watch face is the most reliable setup — and it doubles as your everyday clock.
Keep your iPhone safe, right there on your wrist.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
- Added smaller Safe Zone radius options (10m/30m/50m) for tighter spaces
- Fixed a bug where the watch face background photo didn't update after changing it in Settings
The developer, KAZUTO MATSUBARA, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- KAZUTO MATSUBARA
- Size
- 1.4 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Watch
Requires watchOS 9.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
4+
- 4+
- Copyright
- © KAZUTO MATSUBARA
