Hundreds of apps can follow your movements and share the details with advertisers, retailers and even hedge funds. It's difficult to know for sure whether location data companies are tracking your phone. Any app that collects location data may share your information with other companies, as long as it mentions that somewhere in its privacy policy. You can head off much of the tracking on your own device by spending a few minutes changing settings. Here's how to limit the snooping. How do I stop location tracking on iOS? Some apps have internal settings where you can indicate that you don't want your location used for targeted advertising or other purposes. But the easiest method is to go through your device's main privacy menu. First, open Settings and select Privacy, which has a blue icon with a white hand. Then select Location Services, which is at the top and has a little arrow. You'll see a list of apps, along with the location setting for each. Tap on apps you want to adjust. Selecting Never" blocks tracking by that app. The option "While Using the App" ensures that the app gets location only while in use. Choosing "Always," allows the app to get location data even when not in use. How do I stop it on Android? First, open the Settings on your phone. On the main settings page, tap "Security & location." On the next screen, tap Location, which can be found in the Privacy section. On the Location screen, tap "App-level permissions." You'll see a list of apps. To turn off location for an app, slide the toggle to the left.