GaperGuide – theparkguide – in greater detail:
Since 2007, GaperGuide has been the best way to see Yellowstone National Park and Grand Teton National Park on your own.  GaperGuide is like having a private tour guide, but on your own schedule.  As you drive, GaperGuide gives you the information you need to get the most out of Grand Teton and Yellowstone parks.  GaperGuide will tell you about the wildlife, history and geology of Grand Teton and Yellowstone and it will alert you to upcoming points of interest such as animal habitats and geophysical wonders.  GaperGuide lets you see Yellowstone and Grand Teton at your own pace, and can choose if you want to take advantage of the many Grand Teton and Yellowstone visitor centers, hikes, or picnic areas.  GaperGuide will even tell you when there are bathrooms coming up.  All ages, from the youngest to the oldest, will enjoy GaperGuide’s easy-going narration.  There’s no fixed route through Yellowstone or Grand Teton and no rules about where, when or for how long to stop. GaperGuide stops with you and will be ready to go again when you are.