Good tip and for free !!! My friend told me about an app she said "believe me it could save your life' lool
It sends texts, emails, Facebook, twitter to 5 of your contacts in case of an emergency. It also calls 911 and gives GPS coordinates so you can be located. It's free until tonight so I just downloaded it I must admit it could be very useful (hope will never have to use it though ).
If anyone is interested see where you can find it: http://www.labotec.com/isos/
There was also another cool app but I can't think of the name right now! It taught you how to do certain things if you are in survival mode. There is an app called Pocket first Aid & CPR which is pretty helpful & could save a life.
This app is good but it's a different purpose from isos. it's not about letting people/emergencies know that you're in danger it's about the first aid procedures but still useful though