There are lots of apps that can tell you where the rest stops are, but they don’t know where you’re going. It can be a pain to check the rest stop app, then go back and check your GPS, then go back to the rest stop app, etc. Since Google Maps, on my iPhone, is doing my navigating, it knows the route I’m going to follow. I can ask Google Maps to search for Rest Areas along that route, and it can add one as a stop, giving me the directions. Everything you need, all in one app.

1. Using Google Maps, enter your destination and Start navigating
2. While it is actively navigating, you should see your route as a bold blue line and you should see a magnifying glass in the upper right, tap on the magnifying glass to search for things along your route, you will see a screen that looks like:
   
3. Notice how you can easily search for Gas stations, Restaurants, Grocery stores, and Coffee shops, but you’re not limited to those. If you click the last button “Search” you can look for anything along your route.
4. Tap Search and type “Rest Stops” all the rest stops on or near your route will pop up, including information on how far off your route it is: 3 minutes, 6 minutes, or Quick Detour
5. Tap the stop you like best and Add to Route. Google Maps will navigate to that stop. After your stop it will pick up your route again to navigate to your final destination.

Watch this YouTube video to see exactly how to do it.