Meet Nimb: a smart wearable device with a concealed button that notifies your family or emergency services when you are in trouble. Just hold the button in 3 seconds, and a message with your personal info and GPS coordinates is sent to your safety circles.
Nimb tracks your location in real-time to get you out of trouble. It lets you choose whom to alert. The ring is water and dust resistant. It will be compatible with iOS and Android devices. The battery life lasts 2 weeks. More information is available here.