CodeRED Mobile Alert, also free for Android and iOS from Emergency Communications Network Inc., taps into the CodeRED Emergency Notification System to signal users of nearby crises, such as missing-child notices. You can choose among various alarm sounds - a bell, a horn, a rousing "Woo-Woo" when an alert comes through.
Settings let you choose what sort of issues you want to be alerted to, including severe weather, heat, cold, and marine warnings issued by the National Weather Service.
But you'll get the weather warnings free only for an initial 30 days. Though this may be the best feature, it will cost you - $4.99 per year - after the trial period.
If you are the one in trouble, Emergency Alert, 99 cents by Lighthouse Mobile Solutions for Apple devices, tells friends by e-mail or text and authorities at 911. Just hit the big red button on the screen to send out your status and location. The app also stores personal information about your insurance, emergency contacts, and medical issues.
Disaster Check In, for Android and Apple, by Disaster Check In Inc., is a free app that, with a minimum of taps, notifies a preset list of recipients where you are and that you are safe or in need of help.
You may notify individuals, separate lists of family and friends, or relay your status to all your contacts at once. Reviews say Disaster Check In is a good app for use by children to keep parents alerted to their location and well-being.
When you need to step up, "don't panic," says the opening screen on Free CPR, an iPhone app by Evolving Monkeys L.L.C. "Don't panic" is Step One of five simple steps to administer the most basic lifesaving assistance to someone who isn't breathing. A companion app, Disaster Prep, is an emergency-preparedness checklist and guide, with instructions for assembling a "family emergency kit and plan."