Attention is the deterrent
Most opportunistic confrontations rely on quiet and speed. A sudden, loud siren and a bright, flashing light remove both. They draw eyes, they create a record, and they make the situation expensive and risky for the other person. The goal is not to win a fight. It is to make a threat decide you are not worth it and move on.
Loud and bright, even on silent
A good deterrent has to work regardless of your phone's settings. Holler's siren plays over the mute switch and its strobe lights up the whole screen, so the deterrent does not depend on whether you remembered to turn your volume up. The visual strobe works even if the volume is low.
A record changes behaviour
Knowing that a moment is being recorded changes how people act. Holler starts recording when the alarm fires, capturing the scene as evidence rather than after the fact, and stores it securely so it is there if it is ever needed.
What a phone cannot do
A phone cannot guarantee your safety, and no app can dial the emergency services for you silently. A deterrent reduces risk; it does not remove it. That is why Holler also makes it one tap to call your local emergency number and to bring a trusted contact in with your live location. Holler is not a substitute for emergency services.