How I Built an iPhone Theft Detection System Using Motion Sensors and Screen Time APIs

How I Built an iPhone Theft Detection System Using Motion Sensors and Screen Time APIs

From Programming Tech Brief By HackerNoon by HackerNoon

May 27, 2026 · 5 min

About this episode

The episode discusses the creation of an iPhone theft detection system using motion sensors and Screen Time APIs.

This story was originally published on HackerNoon at: https://hackernoon.com/how-i-built-an-iphone-theft-detection-system-using-motion-sensors-and-screen-time-apis . How I built phone snatch detection for iOS using accelerometer, Screen Time API, and a background location hack. No ML, no hardware. Check more stories related to programming at: https://hackernoon.com/c/programming . You can also check exclusive content about #mobile-app-development , #ios-app-development , #swiftui , #mobile-security , #theft-detection-software , #ios-background-tasks , #cmmotionmanager , #iphone-security , and more. This story was written by: @olegmmv . Learn more about this writer by checking @olegmmv's about page, and for more stories, please visit hackernoon.com . Android shipped Theft Detection Lock in 2024. Apple still has nothing. I built a free iOS app that detects phone grabs via accelerometer and locks selected apps using Screen Time shields. The technical rabbit holes: CMMotionActivityManager turned out useless (reports "Unknown" instead of "Running"), background execution requires a location manager hack to keep the process alive, Screen Time API has two token types you need to apply…

Topics covered

  • iOS development
  • mobile security
  • theft detection
  • motion sensors
  • Screen Time API
  • app development

Keywords

  • iPhone theft detection
  • accelerometer
  • mobile app development
  • iOS background tasks
  • theft detection software
  • CMMotionManager
  • iPhone security

Mentioned in this episode

Organizations: HackerNoon, Android, Apple

Products: iPhone, Screen Time API, CMMotionActivityManager, Face ID

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