I've had a brilliant idea for an app - well, two apps - aimed at young children. The first one will be called Super Magic Puppy Pony Unicorn Fun Time Lite, and I'll give it away for free.

The second one will be called Super Magic Puppy Pony Unicorn Fun Time HD, and it'll be £99.99.

The apps will be identical bar one thing: after five minutes of play, the free version will start nagging the player to upgrade to the HD version. I haven't worked out the exact wording yet, but I reckon something along the lines of "CLICK HERE TO UPGRADE NOW OR MUMMY AND DADDY WILL DIE" should do the trick.

I'm going to be rich!

I've said before that kid-friendly apps are often wicked, and it seems that the Office of Fair Trading agrees: it wants to hear from any parents who reckon they've been tricked by "misleading, commercially aggressive or otherwise unfair" in-app purchasing.

Quite right too. While many kids' apps are perfectly respectable, there are plenty of apps that are designed to trick, not treat.

Parental control

Whenever the topic of regulating in-app purchases comes up somebody immediately blames the parents. "You shouldn't let your child have your password!" they cry, apparently unaware that five-year-olds can perform brute force password cracking much faster than any supercomputer.

The issue here is that even if like me you switch off in-app purchasing and keep your password secret, browsing app stores with your kids is an exercise in frustration and disappointment. "Can I...?" "No." "How about...?" "No." "Why?" "Because grown-ups are wicked and try to trick children." "Waaaaah!"

The OFT means well, but it's not going to stop the chancers. That's up to us, and to the app store owners. For example, Apple now posts an "Offers In-App Purchases" flag on IAP-enabled apps; enabling us to use that flag to filter such apps out of the App Store on our iPods, iPhones and iPads would be trivial to implement, a huge help to parents and wouldn't inconvenience non-parents.

In the meantime, if you have app-crazed kids you can do what I do and avoid free apps altogether. Simply clicking from Top Free to Top Paid gets rid of most of the bad apps, and while it's something of a blunt instrument - you miss out on perfectly good free apps too - it's better than telling your kids that app developers hate children.