If you have a mobile phone, you probably have at least one application, or app. From online shopping to checking the weather, apps offer personalized experiences. Apps keep you connected, but the convenience they offer comes at a cost. While you connect to other people and the world, your app may be connecting to advertisers, businesses, and strangers in ways you can’t imagine. Knowing what apps are, the kinds of data they collect, and what happens with that data can help you protect your privacy—and the privacy of people you love.