Google's new Trusted Contacts app for Android lets you check on family and friends to see if they are safe and OK.
To get started, launch what Google calls its "personal safety app" and add the people you want to stay in close contact with.
The person being tracked needs to have the Android app installed, but trusted contacts can check on the person and view their location via a Web browser. Contacts can also request to see someone's location via browser.
If five minutes pass without the person responding, the app will display the person's last known location. Likewise, if the person's phone is offline, contacts will see their last known location.
If all contacts are using the Trusted Contacts app, you gain more detail on a person's activity. For example, you can see whether the person's phone has recorded movement in the last 20 or 30 minutes and whether their phone is offline or their battery is running low.
Google is not the first company to offer a personal location service. Apple's Find My Friends offers many of the same features, as do safety apps like BSafe, which has the added benefit of working across mobile platforms. You can also find apps designed for college students, such as TapShield, [http://tapshield.com/] that allow students to tap into a campus's security network.