You'll usually want to call emergency services if you're in truly dire straits, but the odds are that your friends and family also want to know if you need help. How do you reach them quickly? If you pick up the Moto E or Moto G LTE, you'll have Motorola Alert at your disposal.
The new app lets you trigger an emergency mode that sends regular alerts and location updates to important contacts. You can also tell people to meet up (at a shelter, for instance), and you can define your home or workplace to let people know that you're in a familiar area. Alert won't work on the Moto X or original Moto G until an update arrives in the near future, but you can still get a peek at it on Google Play if you're curious.