iExit is a universal, US$0.99 app for iPhone and iPad designed to help you find what you need while on the US interstate system. There are plenty of apps with similar features, but there are a few things that put iExit above the norm.
Mike Rose mentioned the app in his piece on summer road trip apps, but I'm going to take a deep dive into iExit.
The app has two modes. The on-the-road view provides information on what's ahead, from campgrounds to restaurants to ice cream shops to hotels. You can filter these results, having the app display only gas stations that dispense diesel fuel for example, or just look for the nearest Wendy's.
That brings us to planning mode, where you can select any state, any interstate and any exit to get the information from the comfort of your home or office. You can save a favorite, and when you are actually near that location, iExit provides alert when you are nearby. You can even specify at what distance from your destination the alert pops up.
In addition to these features, iExit can emphasize things like truck-friendly destinations or family restaurants with playgrounds. Best of all, the app has all the data on board. To test this, I went into airplane mode and the app continued to work just fine.
Although not a navigation app, iExit will link to the web version of Google Maps. I don't think that's a great solution, because you can't get turn-by-turn directions. The developers would be far better off to give an option to send the destination to Apple Maps or third-party apps instead. On the other hand, since you are looking for businesses just off the interstate exit, nothing should be very hard to find.
Road Ahead is a free app with similar capabilities that I liked when I reviewed it last year. The biggest difference is the sophisticated filtering that iExit performs, and the background alerts. I think for some, the small difference between free and $0.99 will make iExit the preferable choice, but Road Ahead is very capable, and seems to help find locations farther away from the interstate exit. Both apps include coupons for discounts at hotels and other local destinations.
iExit and Road Ahead can take a bit of fiddling in the car, which is not a good thing. iExit has a warning when you first open it, telling you that if you crash it's your fault, and not the fault of iExit. My strong suggestion is let your passenger work on your destinations, or get it done before you get behind the wheel.