You swore you wouldn’t do it, but now you find yourself hopelessly addicted to some mobile game (Candy Crush, anyone?). And now you can’t stop yourself from asking Facebook friends to join so that you can advance, or even worse – shelling out real money to move up levels in a virtual game. Or maybe you’re a parent who handed your smartphone to your four-year-old just to “keep them busy for a minute” and ended up with lots of unexpected charges to your iTunes account. Apps can be super-useful for everything from playing games to managing money to tracking your heart rate, but they can also have hidden fees that creep up on you if you’re not careful. Here’s what you need to know:

In-app purchases are those pesky little annoyances that you pay for once you’ve opened an app to do things like get to new levels in a game, get rid of banner ads, or unlock additional functionality of an app that you might want to use. The problem comes in when the developer hasn’t made it clear that what you’re tapping might have a cost. Games, especially those for younger children, are notorious for making it relatively seamless for a kid to tap an icon and keep playing without interruption, clueless to the fact that they just spent your real money. But it’s also frustrating for adults as well to search through a sea of apps to find the one that does exactly what you want it to do, only to find out that the very feature you need is behind a subscription paywall.

One way to avoid an unwanted surprise is simply to scroll through the app description before you download. Most people have a tendency to just tap the download box without actually checking out the rest of the app’s info. If you scroll down past the developer info, you’ll see whether or not there are in-app purchases available and how much they cost. Another really quick way to check is to look at the “Top Charts” in your respective app store. If there is a free app in the “Top Grossing” category, that means there are in-app purchases contributing to that app’s bottom line.

To disable the ability to make in-app purchases without a password on an iPhone, go to Settings > Restrictions then tap ‘Enable Restrictions’. Once you’ve enabled restrictions, you can control what can be downloaded, restrict certain types of content, and require a password for in-app purchases. For Android, go to the Google Play store, tap ‘Apps’, and go to your settings within the Apps category. You’ll find similar content controls and can set a password requirement for in-app purchases. You can also always dispute purchases, as Apple found out earlier this year when they settled a class-action lawsuit.

It might not seem like that big a deal, but when you consider cases like this kid who spent thousands of dollars playing a game downloaded from what he thought was a free app, it’s worthwhile to take a couple of simple steps to make sure you don’t get caught out there. And as with anything these days, even if it’s free let the buyer beware!

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