Regulator PhonepayPlus has noted a 300% increase in complaints from consumers faced with an unexpectedly large phone bill.The regulator said it was working with Facebook to make sure rogue offers and promotions were removed from the site as quickly as possible.In most mobile app stores, it is free games that make their way to the top of the most downloaded charts, so many games makers have opted for the in-app sales business model.Many titles, such as the massively popular Angry Birds, give players the chance to progress more quickly in the game by spending small amounts of money.There are several steps parents can take to protect against the