Anti-Pickpocket alarm: it screams when it leaves your pocket

Every Android phone has a proximity sensor next to the earpiece. It is the sensor that turns the screen off when you hold the phone to your ear. Inside a pocket or a bag the sensor is covered. When the phone is pulled out, the sensor is suddenly uncovered.

Alert24 watches for exactly that change: covered, then uncovered. When it happens while the alarm is armed, the app plays a warning beep and then rings the siren. Because the trigger is the pocket itself, there is nothing to press and nothing to remember once the phone is put away.

Arming by hand is fine for one trip. For daily commuting, switch on the pick-pocket alarm in the Automation panel on the dashboard (the automation icon at the top). The tab then shows Auto Activated, and the app keeps watching in the background. Whenever the phone has been covered in a pocket for a couple of seconds and is then pulled out, the alarm fires.

To avoid alarms every time you check your phone, automation stays quiet in your trusted places, on a saved safe Wi-Fi network, and for 30 minutes after you choose pause on the alarm screen. When the alarm arms somewhere new, Alert24 offers to save that spot as a trusted place. Read more on the trusted places and auto-arm page.

When you answer a call, the phone goes to your ear and covers the sensor. Then you lower it and the sensor is uncovered again. That would look like a pocket exit, so Alert24 does not raise the alarm while you are on a call. On Android 12 and later it also ignores the sensor while the phone is ringing, if you allowed the phone permission.

A trusted place works the same way for automatic arming: at home or at your desk, a pocket exit is normal and no alarm sounds. An alarm you armed by hand still rings everywhere, because you asked for it.