Halo — SOS button

Halo is an SOS app for your own people. An SOS button, a spoken alarm phrase, crash detection and the volume keys: the alert goes to those who can actually reach you in minutes — family, neighbours, a circle of mutual aid. This is not a line to the emergency services. If life is in danger, call the emergency number first.

NO SIGN-UP

No account, no phone number, no email. You enter a name and an address yourself — any you like, as long as your own people recognise you. Nothing is verified, because this data is not for us: it is for whoever comes to help.

FOUR WAYS TO CALL FOR HELP

— An alarm phrase you choose yourself; recognised on the phone, without the internet
— Crash detection — a car accident, a fall, a pedestrian struck
— Five presses of the volume key. Wake the screen with the power button first; the phone can stay in your pocket
— The SOS button

Three of the four work without touching the screen.

SOS SIGNAL BY LIGHT

The camera flash or the screen itself sends a distress signal in Morse code. You can also send your own text. It works with no internet, no group and no permissions at all — right after installing. Where there is no signal, light carries further than a shout.

HOW HALO USES ACCESSIBILITY

The volume-key trigger needs the Android accessibility service: while another app is on screen, the system does not pass hardware key presses to Halo, and there is no other way to notice them. The service does nothing else here. It does not read screen content, collects nothing and sends nothing anywhere. Turning it on is optional — the app works without it, and the other three ways do not need it at all.

THREE CIRCLES

Family — those closest to you. Automatic triggers always go here.
Home — the neighbours in your building. The alert belongs to the address, not the person: a neighbour needs to know which door to knock on.
Mutual aid — whoever happens to be nearby.

An alert goes only to the circle it was raised in.

WHEN AN ALERT ARRIVES

A full-screen alert with sound appears over the locked screen. Whoever responds sees your place on the map and can open it in a navigation app. When coordinates are not enough — a stairwell, an underground car park, a forest — Bluetooth search covers the last few metres. It works without the internet.

PRIVACY

There is no constant tracking: location is sent only during an alert and on a request for a child's location. Maps are OpenStreetMap, with no third-party trackers. Statistics are anonymised. There will never be ads.

KNOWN LIMITATIONS

Halo is an SOS button for your own people, not a rescue service: the app does not call the police or an ambulance. Crash detection cannot tell a real accident from a hard knock with full certainty — hence the fifteen-second cancellation window. The volume keys need the screen awake. Bluetooth search shows warmer and colder, not a point. A light signal only helps where there is someone to see it, and it drains the battery.

SUBSCRIPTION

Sending alerts costs $1 a month or $10 a year, with the first 14 days free. Receiving alerts is always free: you can help others without a subscription. A child's phone does not need one. The light signal works without a subscription.

Recent changes:
Faster start: only notifications are required now, so alerts from your people reach you right away. Location and microphone can be granted later — Halo will remind you on the groups screen.
The journal no longer shows a group's old alerts from before you joined it.