Since the app is intended to be used while sleeping, it would be pretty easy to include a preprogrammed address in the 911 message (perhaps with a geolocation '

Since the app is intended to be used while sleeping, it would be pretty easy to include a preprogrammed address in the 911 message (perhaps with a geolocation 'sanity check' just in case the wearer is traveling). I think notifying a friend or family member is probably the most important thing. They can follow up from there. Text-to-911 is growing in availability (in the US, anyway), but it's far from universal: http://transition.fcc.gov/pshs/911/Text_911_Deployments.pdf http://transition.fcc.gov/pshs/911/Text_911_Deployments.pdf