Family Link is essentially a new type of Google account that’s only meant for users under the age of 13. It allows parents who are comfortable with tossing their kids into Google’s data-mining net to manage the apps their children can use, monitor and set time limits on usage, and remotely lock the device at bedtime.

Google first released the app in March, but only for testing—users had to request an invite. The functionality is now available to everyone in the U.S.

Here’s how it works. When setting up the child’s Android device for the first time, Google (GOOGL) will as usual ask for an account that it will tie to the smartphone or tablet. All you need to do is set up a new account and enter the kid’s birthdate—if they’re under 13, Google will automatically install Family Link on the device. By entering your own account details where requested, you will get the ability to monitor the device from your own.

Of course, many kids will already have Android devices, and here’s where Family Link hits a snag. Although it is possible to manually download the app for such devices—which must run Android 7.0 or up—reviewers have been angrily pointing out that it’s not possible to use a pre-existing account. In other words, you’ll need to set up the phone with a new account.

The parent also needs to be running the Android Link app on their phone in order to manage what’s happening on the kid’s device. That doesn’t mean the parent needs to be an Android user, though, as there’s also an iOS app for that.