Microsoft has recently updated its page devoted to information about Windows Phone inserting a new feature that will come with the Tango update.
A new icon will be added in the notifications bar hidden link at the top of Windows Phone, this icon will be displayed only when an application uses the location service on Windows Phone(GPS or network).
This new icon (you can see in the picture above), will be displayed only if we enabled the "position" on the settings of Windows Phone, which allows applications to precisely know our exact location.
Microsoft informed that this feature will be included with the next update of Windows Phone (Tango) , which will first pre-installed on new devices and later as an upgrade for the "old" devices.
"After the new devices are out, we'll start the process of working with mobile operators to bring an update to current customers"
Via TheVerge