Emergency Contacts is the fastest way to display important health or contact information in an emergency
You can store anything, though I’d recommend someone to call in the event of an emergency, as well as any allergy or medical information that might be useful.
Yes! iOS 8 allows custom Today Extensions that can be displayed even while the phone is locked with a passcode. You don’t need to sacrifice security for convenience here.
Emergency Contacts will run on any phone that can run on iOS 8 or higher.