Last Friday, it was confirmed that the class action lawsuit can go ahead after a San Jose judge denied Apple's attempt to get it dismissed.
The parents allege in their suit that children are being allowed to make purchases via a "currency" within free iOS games without first requiring the permission of their parents.
The suit alleges that the "highly addictive" nature of the games can work to "compel children playing them to purchase large quantities of game currency, amounting to as much as $100 per purchase or more".
Many games use the business model of being free to download, but then imposing an in-app charge for the purchase of additional content, such as extra levels or items.
For example, the children's game, The Smurfs' Village, uses "smurfberries" as the in-game currency for users to purchase for a range of levels up to $60.
The same approach is true for recent games featuring the characters from Ice Age and The Simpsons.
The Daily Mail has reported that a British 7-year-old racked up a £1,300 bill on an iPad last year in just four days after his mother downloaded the Tap Zoo app for free.
In the lawsuit, the US parents claim that children can still make several purchases after a password has been initially entered, enabling them to use their parent's iTunes account, where credit or debit card information is stored.
Their case can now go to court, but Apple is likely to fight the charges as it says that parents can easily activate security settings to stop children running up charges. The firm has also recently increased its security safeguards on iTunes.
> Apple says eBook price fixing claims 'simply not true'
> Apple, Samsung agree to settlement talks