When a photo is taken
Alert24 uses the front camera as a witness. It never records video and never shows a preview. When one of the events below happens, it takes a single photo, stores it in its private folder on the phone and, if you allowed location, adds the address. The shutter sound is switched off.
Each photo is tagged with the event that caused it, so the gallery can be filtered later. These are the triggers:
- Wrong device unlock: after the number of wrong attempts you set, on the phone's own lock screen (needs device admin)
- Wrong Alert24 PIN: wrong entries on the app lock screen or on the alarm screen
- Alarm start: every Don't Touch My Phone, pick-pocket, charger, earphone or drop alarm takes a photo as the siren begins
- Remote request: a Take Picture command sent from your other phone or the web
- Lost mode: while the phone is marked lost, every screen-on and unlock is photographed
- New app installed: a photo when an app is installed, on by default in Settings
Set the number of wrong attempts
The wrong-unlock photo is the one most people want first. It takes a minute to switch on.
- 1
Open Intruders Pictures from the menu
Tap the menu on the dashboard and choose Intruders Pictures. The switch at the top enables the device intruder alert.
- 2
Allow camera and device admin
The camera permission is needed to take the photo. Device admin lets Alert24 be told when a device unlock fails; Android does not share that with normal apps. This step also asks you to sign in with Google.
- 3
Choose Pin Attempts: 1, 2 or 3
Pick how many wrong device unlocks trigger a photo. One is the strictest; three ignores your own typos. The photo comes with a siren that stops when the phone is unlocked correctly.
Gallery with type filters, time, address and map
The Intruders Pictures screen lists every photo with its date. Use the filter at the top to show only one kind: Device Intruders, App Intruders, Anti-Motion, Anti-Pick-Pocket, Charger Intruders, EarPhone Intruders, Phone Drop, Remote Captures, Find My Device, App Installed or Device Lost.
Tap a photo to see it full size with the trigger type, the exact time, the street address and a small map. A View in Maps button opens the spot in Google Maps. This is how you tell a roommate's curiosity from a stranger in a cafe.
Delete photos you do not need
Most photos will be of you, your family or a friend who borrowed the phone. Open a photo and tap the trash icon, confirm, and it is gone from the phone. If the photo had been synced to your Google account, the copy in the cloud is deleted as well.
The list keeps the most recent 100 photos. In the free version, the first 5 photos open at full size and the rest are blurred until you upgrade to Premium.
Permissions it needs and why
| Permission | Used for | Without it |
|---|---|---|
| Camera | Taking the photo | No photo is taken; alarms still ring |
| Display over other apps | Taking a photo from the background and showing the alarm screen | No background photo and no alarm screen |
| Device admin | Being told about wrong unlocks on the phone's lock screen | No wrong-device-unlock photos; other triggers still work |
| Location (optional) | Address and map on each photo | Photos are saved without a location |
Related features
Phone Access Snap
A photo of every person who unlocks the phone, grouped by face, kept only on the phone.
Learn moreApp lock
The PIN, pattern or knock code that protects Alert24 and stops the alarms. Wrong entries are photographed.
Learn moreLost mode
Mark the phone lost from the web and get a photo every time someone wakes or unlocks it.
Learn more
Intruder selfie: questions
How do I see who tried to unlock my phone?
Switch on the device intruder alert in Intruders Pictures and set Pin Attempts. After that many wrong unlocks, a photo is saved in the gallery with the time and place. The step-by-step guide walks through it.
Does the person know a photo was taken?
No sound plays and no preview is shown. If an alarm is ringing at the same time they will obviously know the phone is protected, but the photo itself is silent.
Are intruder photos uploaded anywhere?
Only if you sign in with Google. Then they sync to your own account so you can see them remotely. Without sign-in they stay on the phone.
Why does it need device admin?
Android only tells device-admin apps when a lock-screen unlock fails. Alert24 uses that single signal to take the photo. It does not use device admin to lock or wipe the phone.
Is the intruder selfie free?
Yes. The gallery on the phone is free with ads. Premium opens galleries beyond the first 5 photos in remote views and removes ads.
Know who picked up your phone
Install Alert24, switch on the intruder alert and set your wrong-attempt limit. Free on Google Play.