Add the National Parks Conservation Association to the number of organizations and developers offering a phone app to help you negotiate the national parks. One of the big differences here, though, is NPCA is giving its app away for free. Another is its emphasis on park wildlife and nature in general.

The app works on iPones, iPads, and iPod Touch devices. Developed for NPCA by the folks at eNature.com, these apps focus on wildlife and ecosystems of 50 national parks. According to a release from the park advocacy group, "the guide includes bird portraits, call recordings, information about endangered and poisonous species, range maps, and wildlife. Users will also find current news about featured parks, access and reservation information, and directions to park visitor centers."

At the heart of this mobile app is eNature’s comprehensive, geographically segmentable database of U.S. wildlife, both animals and plants.

“We are pleased to offer this innovative and informative mobile field guide free of charge to national park visitors,” said Megan Cantrell, NPCA's senior coordinator of member engagement. “The new guide will enhance the experience of park visitors by providing a fun, educational companion for families and nature-lovers to learn about the many natural treasures that parks have to offer.”

From seashores and recreational areas to scenic riverways and historic sites, the field guide mobile app features 50 national parks across the country that support critical wildlife habitats. Among the many national parks featured include: Yellowstone, the Grand Canyon, Yosemite, Cape Cod National Seashore, and Gettysburg National Military Park. To view a complete list, visit: http://www.npca.org/parks/app.html

“Our new field guide will help engage and educate a new generation of advocates for our national parks,” said Ms. Cantrell. “The more people who understand that our national parks are America’s legacy to our children and in urgent need of care and repair, the better chance we have at protecting them for the future.”

According to the NPCA release, "eNature.com’s core content of wildlife information includes almost 6,000 individual species and is the same data set used to create the printed Audubon Field Guides. Data has been carefully reviewed and vetted by leading biologists, zoologists and other natural history specialists. eNature.com has consistently been one of the Internet's most-visited sites for nature and wildlife information and has won numerous awards and accolades."

“With eNature’s unsurpassed wildlife content base, we are able to create a mobile app guide uniquely capable of targeting specific parks so users can quickly identify and enjoy the wildlife they come across,” stated Tom McGuire, eNature’s President.

The National Park Field Guide is available at: http://bit.ly/NPCApp, or visit the Apple App Store from your iPhone and search Park Guides.