How it works: free fall, then impact
While a phone is falling, its motion sensor reads almost zero gravity. When it hits the floor, the sensor sees a sharp spike. Alert24 looks for those two events in order: a short free fall of at least a fraction of a second, followed within about a second by a hard impact.
Only that combination counts. Shaking the phone, a bump on a table or a jolt in a bag does not produce a free fall first, so it does not trigger. A phone that slides off a desk, is knocked out of a hand or thrown does.
- Uses the accelerometer only, no internet or location needed for detection
- At most one drop alarm every 10 seconds, so a bounce is not counted twice
- No warning beep: the alarm starts as soon as the drop is recognised
What it records
A drop is handled like any other Alert24 alarm. The alarm screen appears, the siren rings with flash and vibration if they are switched on, and the front camera takes a photo at that moment. The photo is saved in Intruders Pictures with the type Phone Drop, the time, and, if location is allowed, the address and a map.
The siren stops when you enter your PIN, pattern, knock code or fingerprint. If it was you who dropped the phone, that takes two seconds. If it was somebody else, the photo tells you who.
Turning it on in Settings
- 1
Open Settings from the dashboard menu
Tap the menu icon on the Alert24 dashboard and choose Settings.
- 2
Switch on Drop Detection
It is in the General section. The switch takes effect immediately and stays on until you turn it off.
- 3
Check camera and overlay permissions
The photo needs the camera permission and the alarm screen needs Display over other apps. Both are requested during the first-run setup.
Works well together with
Drop detection: questions
Will it go off when I drop my phone myself?
Yes, if the fall and impact are hard enough. Enter your PIN on the alarm screen to stop it. Most people find that a fair trade for knowing when someone else drops it.
Does it use extra battery?
It reads the motion sensor in the background. The speaker, torch and camera are only used when a drop is detected.
Is drop detection free?
Yes. It is part of the free version, with ads.
Find out when your phone hits the floor
Install Alert24 and switch on Drop Detection in Settings. Free on Google Play for Android 7.0 and later.