I've got the back
You watch the front.
This phone watches the back.
The rear lens sees best. Let your arm hang and walk as usual, with the lens facing behind you.
Your arm swings as you walk. The picture is read as if the camera were held still and upright.
When someone closes in, or the gap drops all at once, it speaks in your ear first.
A night street, a strange block, the walk home, a food-court table. Anywhere your back is open.
It does not identify anyone. Video is not saved and does not leave the phone. The eye is saved on this phone after one download.
bodyguard
Waiting for the motion sensor
If you can see what's behind you, the lens is aimed right. Don't turn the screen off. Dim it.
Rehearsal
In the hand it shakes. Below, the view is held upright.