Every kid who's begged their parents to buy them a phone has used the, "I can call you so you know I'm safe" line. And every parent who fell for it learned their kids are actually TERRIBLE at checking in, so you're going to love this as much as your kids hate it...
A mom in Houston, Texas has invented an app that FORCES your kid to call you back. It's called Ignore No More. When a parent calls their kid and the kid doesn't answer, the app locks their phone and only gives them two options: Call their parent back or call 911. So they can't text, play games, or use apps until they call their parents back and get the unlock code.
Ignore No More costs just $1.99 but it's only available for Androids. Apple doesn't allow apps to lock up the phone the way this does.