Change which apps track you

From Time, an article by Lisa Eadicicco about staying under the radar:

Many of the apps we use everyday, from Facebook to Google Maps and Yelp, need to keep track of our location in order to provide their services. This is how Google Maps knows the fastest route to your destination and why Yelp is able to recommend nearby restaurants.
While some apps may need to monitor your location to provide the best experience, not all of them necessarily need to know your whereabouts. Limiting the number of apps that can access your location can also help you squeeze extra battery life out of your phone.
It’s possible to restrict individual apps from using your location, and with certain apps you can also set more specific restrictions. For example, on the iPhone you can choose to have the app always monitor your location, only track it when the app is in use, or you can set it so that an app never sees your location. These choices may vary depending on the app.
This option can usually be found in your phone’s settings menu under the privacy option. From here, you can also choose to turn off location services completely if you’d like to stop all apps from harvesting your iPhone’s GPS data.
Check out the video above to learn exactly how to hand-pick which iPhone apps have access to your location.

Rico says you're not paranoid, just aware... (And Rico's already done it, just in case.)