Why a shake
In a moment that turns tense, you should not have to unlock your phone, find an app and hit the right button. A shake is something your hands can do on their own, in a pocket, in the dark, without looking. That is why Holler makes a shake the signature way to raise the alarm: the less you have to think, the faster help is on its way.
What one shake does
The instant you shake, three things happen at once. A max-volume siren and a full-screen strobe fire, even if the phone is on silent, to deter a threat. Recording starts, capturing the scene as evidence rather than after the fact. And the one trusted contact you chose is sent your live location, on iPhone or Android, with a one-tap way to help. A button to call your local emergency number is always right there too.
Arm it for your walk home
You arm a walk-home session before you set off. From then on the shake works even with the phone locked and in your pocket, so it is ready the moment you need it and not a second later. When you arrive safely, you end the session and Holler goes quiet.
It will not go off by accident
Holler only listens for a shake while a walk-home session is armed, and it takes a firm, deliberate shake to fire, not the everyday jostle of a bag or a pocket. Outside a session, nothing is listening. If you prefer, you can also trigger the exact same alarm with an on-screen button, the Lock Screen widget, or the Action Button on iPhone 15 Pro and later.
Private by default
Your live location is shared only while an alert is active, and only with the contact you chose. Holler is not an always-on tracker, your data is never sold, and it is built GDPR-first with EU data residency. The shake raises the alarm; it does not start watching you.
What it cannot do
A shake cannot dial the emergency services for you: no app can do that silently, on any phone. Holler brings a trusted contact in with your live location and makes it one tap to call your local emergency number yourself (112 in Europe, 999 in the UK, 911 in the US). A deterrent lowers risk; it does not remove it. Holler is not a substitute for emergency services.