A good way to see an overview of parks, but only works as a stepping off point.
Community Review for National Parks by National Geographic
I only used the free version with my students, if you pay an extra 12 or 13 dollars you can get more in depth park guides which may glean more educational value. The free version really only acts as a list of the most popular parks, once kids click on a park they can see a couple pictures of the park, then I had them click on map to explore where the park was, then click on stats for a couple of interesting facts. Once that happened they would go to other websites and explore the park online (a great way to go over the 50 states is looking at state parks). So this really just acted as an intro to the parks and a quick overview and location tool. It is the most visual and engaging way for them to look over our nations biggest and best national parks (as far as a slideshow like quick flip through). If the $12 expansion pack was cheaper or free this would most likely make a much better educational app, be awesome if they had a discount for educators!
How I Use It
I used it with 5th graders to have them report on and research national parks (as a way to help out with knowing the 50 states). It was only used in the very first stages of research for them to get an idea of where the parks are and what they look like. They get to see about 3 pictures of the park, location, and info like how many people visited the park last year. So they didn't use this past helping to choose which park they would start looking more into on google.