It's an irritation well known to the parents of teenagers: you buy them a mobile phone, on the pretext that it provides a measure of security – wherever they are, they're always contactable. Except they aren't, because they never answer it or ring you back.

We should have foreseen this. There were no mobile phones when I was a teenager, but if I'd had one I'm sure I wouldn't have answered it when the helpful warning "Mum" appeared on the screen. As a parent, I now know how sharper than a serpent's tooth it is to have to send half a dozen increasingly desperate texts over the course of a day just to secure a reply along the lines of "Yeah fine" or "In Laos".

Now one anxious mother has struck back. Sharon Standifird, from Texas, has come up with an app that makes it impossible for your kid not to call you. Ignore No More (currently available for Android, with an iPhone version in the works) enables parents to lock thankless children's phones remotely, turning the screen black. They can't play games, consult Facebook or call anyone else until they return an ignored call or text (they can, however, dial the emergency services).

The new app, like the popular tracking feature that allows you to monitor another phone's whereabouts on a map, has one major drawback: you have to get hold of your child's phone long enough to download and activate it. And if your kid has told you his security passcode, then you should probably be more worried about how naive he is.