Your iPhone can track your location with a remarkable degree of accuracy thanks to the data it gathers from its GPS sensor, Wi-Fi and cellular radios, and even its Bluetooth chip.

That’s why when you open the Maps application, you’ll see a blue blob marking your current location. It’s also the way Find My iPhone and Find My Friends work. But it’s not just Apple apps that uses the location data it gathers. Several third-party apps, such as Google Maps, use it too.

Thankfully, for the sake of your privacy, iOS makes it very easy to see which apps have permission to use location data and which apps are using it currently.

When you download an app that wants to track your location, an alert will pop up on screen asking if you give permission to share your location with the app. If you say no, the app won’t be able to track where you are and any features that rely on that data won’t work.

The magic all happens in the Privacy section of the Settings app. Here, you can switch Location Services off completely by tapping on Locations Services and toggling the switch on the next screen to off. If you do that, no app, including those made by Apple, will have access to your location.

You control how iOS shares your location in Location Services.

You control how iOS shares your location in Location Settings

The next setting on that screen allows you to control how your location is shared with other people. Tap it and you can choose to share your location. If you have more than one iOS device registered with your Apple ID, you can control whether they share their location too. And you can also see which family members can see your location, and revoke that permission if you choose.

Choose who to share your location with.

Choose who to share your location with

At the bottom of the Location Services screen is a list of apps. These are all the apps you’ve allowed to access your device’s location data. Next to the name of the app is one of three settings: always, never, or while using. Tap on the name of the app to change the setting. Some apps allow you to choose from always or never, and some never or while using.

Choose how apps access your location.

Choose how apps access your location

In addition to apps, there are two further groups; Apple Watch Faces and System Services. The first of these allows Watch faces to access your iPhone’s location for Watch complications like sunrise and sunset times and phases of the moon. System Services allows you to control which elements of iOS can access your location. These include location-based iAds, so if you don’t want Apple’s advertising network to know where you are, this is the place to revoke permission.

System Services allow you to control how iOS services access location settings.

System Services allow you to control how iOS services access location settings

There’s one more thing worth noting about Location Services. You might notice the location arrow icon next to the name of an app. This indicates that the app has recently accessed your location (purple arrow), accessed it within the last 24 hours (purple outline), or a grey arrow, which indicates the app has a geofence (say a Reminder for when you leave the house) in use.

And that’s how you control how iOS accesses your location!