In one sentence, describe what the following article is about:

It's the app that resembles a red location marker on a green map with the letter "G" on it.  Download Google Maps from the App Store and sign in with your Google account if you haven't done so already and make sure location service is enabled. Tap a location on the map or search for one by typing your destination's name or address in the search bar at the top. This will start the route navigation. It's the red button at the bottom-right of the screen. Tap a location on the map or search for one by typing your destination's name or address in the search bar at the top. This will resume navigation with the new address.

Summary:
Open Google Maps. Select a destination on the map. Tap Start. Tap Exit. Select a new destination on the map. Tap Start.