Warning: Your iPhone is watching every step you take

The feature is difficult to find and the user will not stumble upon it easily while discovering other features.

It might be shocking for iPhone users to know that every single movement of theirs is tracked and stored on their handsets. This means that every place the iPhone user has visited, carrying the phone along, will be tracked and a chilling history of their movements will be available.
This is possible through an iPhone feature called 'significant locations' found in settings. The feature is difficult to find and the user will not stumble upon it easily while discovering other features. According to Apple, a log of all the places recently visited, as well as how often and when you visited them, will help your phone to learn which places are "significant" to you. 
Also, this information is used to provide you with personalised services, "such as predictive traffic routing, and to build better Photos Memories".
Clarifying that the history of places visited is encrypted, Apple says the log will never be shared without the user's consent. Moreover, the significant locations feature requires Face ID or Touch ID to unlock first.
The feature can be found by clicking on Settings (an app with an icon which looks like a little cog), then click on 'Privacy', Open up 'Location Services' and scroll right down to the bottom of the menu and press 'system services'. This will take you to 'significant locations' feature which tracks your movement using 'Location services uses GPS and Bluetooth (where those are available) along with crowd-sourced Wi-Fi hotspot and cell tower locations to determine device's approximate location. 
Fortunately for those who find the feature intrusive, the Location Services can be turned off, reported Metro.co.uk.