The front camera watches
Protection starts with one tap and stays on until you tap Stop. With the screen off, the camera really does close.
The image never leaves the device
Is someone reading your screen?
Right now, over your shoulder. Bisbi uses the front camera to notice when that happens and warns you with a discreet vibration. No photo in the cloud, no account to create, no server.
No account to create
Works in airplane mode
The essentials are free
How it works
It does not flag everyone who walks past you
The front camera sees a cone in front of the device. Inside that cone, the closest face is yours, and it never triggers an alert. What matters is a second face, behind yours, turned towards the screen.
You: the closest face, always ignored
Someone else, inside the field: that is the alert
Outside the field: the app does not even see it
The device works out which face is yours
The closest face is yours and never triggers an alert. Whoever shows up behind it, turned towards the screen, is what matters.
The warning arrives by touch
Two short vibrations. You notice without looking away, and the person behind you does not notice they were detected.
The indicator
A floating dot that says the one thing that matters
It sits on top of any app, you drag it wherever you like, and it can stay invisible while everything is calm.
Green
Nobody but you.
Amber
There are people nearby, but nobody turned towards your screen.
Red
Someone is looking. The phone vibrates right away.
Privacy
A privacy app that does not collect yours
The list on the right is short, and it exists. An app that swore it sends nothing at all would be lying, and lying in a privacy policy is the kind of thing that gets an app pulled from the store.
Never leaves your device
- The camera image. Frames are analysed in memory and discarded.
- Any measurement of your face. The app keeps no biometrics and does not know who you are.
- What is on your screen. Bisbi looks outwards, never inwards.
- Intruder captures, which stay in the app's private storage.
- Name, email, phone, contacts, location or list of installed apps.
This, and only this, does leave
- Anonymous operational events: protection started, alert fired, camera lost.
- The app version and whether the subscription is active.
- A random install identifier that dies when you uninstall.
No image, no face measurement, no head count and nothing that points back to you. It exists to find faults and to know whether the app is being used.
Questions
What people ask before installing
Is the camera on all the time?
Only while protection is on and the screen is awake. When you turn the screen off, the camera is genuinely closed, not paused. And protection never turns itself on.
Does this not destroy the battery?
The analysis does not run on every frame. The device compares frames at a very low resolution and only runs face detection when something in the scene changes; sitting still, the cost drops to almost nothing. The pace also slows down by itself when the battery is low or the device gets warm.
Can you see my photos or my screen?
No, and it is not a matter of trust: there is no path for it. The detection model ships inside the app, the analysis happens in your device's memory and the frame is discarded straight after. You can switch on airplane mode and protection keeps working exactly the same.
Is this face recognition?
No. The app keeps no measurement of your face and does not know who you are. It tells you apart from an onlooker by the size of the face in the image, which is a reading of distance, and that information goes away with the frame.
Does it work in the dark?
It works with the light of a bus at night or of a café, because the front camera can still make out the outline of a face. In total darkness, no - no ordinary camera can see. At that point there is not much to read on your screen from the side either.
Why do I have to watch an ad to start?
A rewarded ad unlocks 24 hours of protection, and it is what pays for the development of the free version. Protection already running is never interrupted when that window ends. With the subscription, there are no ads at all.
Do I need an account?
No. The app works anonymously. A login only exists if you subscribe to Premium, so the licence can follow you to another device.
Install it and switch it on with one tap
Android 7.0 or newer. It only needs camera permission.
No account to create
No image ever sent
Works in airplane mode