I had location history enabled for Google Maps and didn't know it. I found it interesting to see which spots Google logged for me over the past week or month or year, and I don't plan on disabling the service. Google states that your location history map is private and visible only to you, but it's nice to know that I can delete portions of my location history or all of it, as well as disable the feature from tracking me in the future.
To see if you have location history enabled, head to your Google Maps Timeline. In the belt below the map Google will tell you whether location history is on or off and let you enable or pause it. (You can also find this setting in the Personal info and privacy section on your Google account page. Scroll down to the Places you go area click the toggle switch to turn it off.)
Disabling location history, however, does not remove your past history. If you'd like to erase the locations Google has stored for you, click the gear icon in the lower-right corner of your Timeline map and choose Delete all Location History.
You can also delete your whereabouts for a single day or even a single stop of a single day. Choose a day from the menu in the upper-left corner of your Timeline map. You'll then see to the left of the map a list of your stops for that day. Click the trashcan icon at the top of the list to delete the location information for the entire day, or click the triple-dot button next to a stop and select Remove stop from day to delete just that location.
For iOS users who want to disable Google's location reporting from your iPhone, you will need to disable Location Reporting from the Google search app or another Google app on your iPhone, such as Google+.
For the Google search app, tap on your profile pic in the upper-left corner to open Settings. Next, tap on Privacy, tap Location and Location Reporting and then choose Do not report. You could leave Location Reporting enabled but prevent Google from storing your history by tapping Location History from the Location screen and then choosing Do not store.
The process is similar to the Google+ app, tap the hamburger button in the upper-left corner and then tap the gear icon to open Settings. Tap Location History and you'll be able to disable both Location Reporting and Location History.
You can also see which apps are using location services on your iPhone by going to Settings > Privacy > Location Services.
For Android users, the process is streamlined. Go to Settings > Location > Google Location Reporting. For Location Reporting, tap the slider to turn it off.