iOS has a dedicated Privacy menu in Settings, which is the best place to start. Here you can decide which apps have access to specific categories of information on the iPhone (your calendar, contacts, photos and so on) You can give location tracking permission on an app-by-app basis or turn it off altogether. Apple says it uses anonymous and encrypted location data to power its traffic maps and to determine the popular spots (restaurants, bars) in a certain area.”]
Source: https://gizmodo.com/how-to-lock-down-your-privacy-settings-on-ios-1779406136