(ARA) – The app world is booming and today there are more than 1 million mobile apps available for download through online stores run by companies like Apple and Google. Many apps are available free of charge and collect user data for advertising purposes, raising the question: What is the true cost of these “free” apps?

“While there may be no monetary charge to download an app, it might mean you agree to let the app maker collect and use your personal information, like your email address, for marketing purposes,” says Chris Babel, CEO for TRUSTe, an online privacy solutions company. “Ideally, this data collection would be revealed in the app’s privacy policy, but many apps don’t have these policies. Even those that do have one often burry key disclosures and make them very difficult to find.”

Smartphones today collect and store a wealth of personal information because they’re always “on,” and typically go wherever their users go. Consumers store extensive contact information, calendar data, and personal videos and photos on these devices. Modern smartphones may also contain GPS technology capable of collecting precise data about the phone’s movement and location in near real-time.  

“Personal data collection online has been happening for years on traditional PCs,” says Babel. “The difference today is that these ‘computers’ now sit in our pockets in the form of smartphones, and are capable of collecting more types of data, in greater quantities, than ever before. It’s a far more complex ecosystem and it can be difficult for consumers to understand what’s happening with their data. ”

Unwelcome data collection on smartphones can lead to unwanted and intrusive advertising, and increase the risk of data breaches as companies build ever-larger databases of personal information profiling consumers. Before you click that next free download, TRUSTe recommends taking these steps to protect your privacy:

Look for a privacy policy

In early 2012, the California Attorney General struck an agreement with all major app store operators stipulating that apps in their stores must contain privacy policies to comply with California law. A TRUSTe analysis of the top 50 Android and iOS mobile apps at the time, however, found only one in three had a privacy policy. Moreover, these apps that had policies typically did not optimize them for reading on smartphone’s smaller screens and lacked clarity over whether certain disclosures applied to the app or to the parent company’s website.

A study conducted a few months later by the Future of Privacy Forum found improvement in the app marketplace, with 61 percent of top apps in the study featuring privacy policies. If you can’t find a privacy policy for an app, or find one but can’t understand it, think twice about downloading that app. Look for apps that offer easy-to-find, easy-to-understand privacy policies. Mobile apps certified by TRUSTe (bearing TRUSTe’s green privacy seal of approval) will always have privacy policies in clear, easy to understand terms for smartphone users.  

Set app and smartphone privacy settings

Many apps contain privacy settings that can control behaviors like what information the app collects, how it interacts with other apps or a user’s contacts, and how it communicates with and alerts the app user about its background activity. In some cases, these settings may have their own section under a “privacy” tab within the app, but more often than not these privacy settings are found alongside standard settings within the app, like volume levels or sound effects. 

“We commissioned a Harris Interactive survey and found that nearly three quarters of the population worries about their privacy when using mobile apps,” says Babel. “App developers not only have a responsibility to provide consumers with mobile-appropriate privacy disclosures, but also meaningful choices about how their data is collected and used.”

The settings tab of your smartphone operating system (like iOS for Apple devices) may also contain important privacy choices, allowing you to control the types of personal information that apps may collect from the device. Depending on your device, these settings may also provide you with granular privacy control over apps, preventing one app, for example, from collecting GPS data while allowing other apps to collect this data.