Your daughter is on a date and isn’t home by her curfew. Your son went out with a group to a nearby city and is overdue for a check-in. Your spouse is two hours late getting home from work, and you’re beginning to worry.

Thanks to smartphone apps that can help you track your loved ones, these moments no longer have to be panic-inducing. Even if your teen chooses not to answer his phone or return a text, many of these apps allow you to locate him anyway.

These apps generally do a very good job of locating where someone is within a radius of couple of hundred feet or less. That’s because most smartphones are built with GPS receivers that pinpoint the phone’s location. Satellites track the phone’s movement and then triangulate where it is. 

Related: 25 Texting Acronyms Every Parent Should Know

life 360 appLife360 (for Android, iOS)

Life360 allows you to set up a “family circle” and see the location of members of your circle on a map at any time. A one-tap check-in button allows kids to notify parents that everything is OK. The app can send automatic notifications when a member of your circle reaches school, work or home. The app is free, but some options do require users to buy a premium subscription.

mama bearMamaBear (Android, iOS)

Like Life360, MamaBear allows you to see your family’s whereabouts on a map, and it can send alerts when they leave and arrive at certain locations you designate on the map. However, this app also allows you to see what your kids are posting on social media sites like Twitter and Instagram. And it can monitor teen drivers in your network to let you know where they are and if they have exceeded speed limits. The app is free, but some options require you to upgrade to a premium account.

MMGuardianMMGuardian (Android)

This app allows you to find out where your child is at any time, or it can automatically send you a report on her location at pre-set times. It has a wide range of parental controls that let you:

  • lock the phone to prevent your child from using it at certain times (like bedtime)
  • block apps your child is not allowed to use (like WhatsApp and Snapchat)
  • block adult websites
  • get detailed reports of browsing history
  • get call and texting data to see who your child talks to and for how long

family mapAT&T’s Family Map and Sprint’s Family Locator

These locator tools offered by cellular providers let parents determine where their teens are at the press of a button. They can send you the whereabouts of your child at pre-set dates and times, though each one has a monthly charge.

Related: 7 Ways to Keep Your Kids Safe Online

A surge of interest thanks to disasters

The number of people who use geolocation apps has exploded in recent years, says Julie Mullins, director of marketing and communications for Life360. The idea for these apps grew out of tragedies such as Hurricane Katrina in 2005 and the Asian tsunami in 2011, when families became separated and reuniting with family members was difficult. “In 2010, when iOS allowed apps to run in the background, we saw a huge spike in growth of people using it after the Japanese tsunami and tornadoes in the Midwest,” Mullins says. “But then we saw people using it every day to let each other know everything was OK.”

Matthew Gerst, director of state regulatory and external affairs at CTIA-The Wireless Association, says the industry is concerned about privacy issues and notes that you can turn off your phone’s geolocation if you don’t want to be tracked. Clearly, however, there’s a demand by families and even teens, some of whom who want the comfort of knowing that if they’re in trouble, all they have to do is send an alert.

Related: How to Keep Apps from Learning Too Much About You

Ronald Agrella is a freelance writer and former editor of The Boston Globe’s Boston.com.