I first met David Bradbury a decade ago when he was playing a version of polo on mountain bikes in Burlington, Vermont. When I later had to write a story for The Boston Globe on hiking Vermont’s tallest peak, Mount Mansfield, I wisely chose David to take me to the summit. Of course, he chose the most challenging route, up the Hell Brook Trail. When he’s not hanging with his wife, Emily, my favorite PR maven in Vermont, or his young children, you can often find him making first tracks down Stowe in the early morning hours. So when I heard that David is on the board of a Vermont company called Green Mountain Digital, creating nature-based apps for Audubon Field Guides, I knew the product had to be good. So far, they have 30 apps categorized by geographic region (Texas, Florida, New England, etc…) and type of critter (birds, insects, butterflies, fish). I checked out the Audubon Birds New England app and found the photographs and songs of the 370 birds to be of the highest quality. Just launched is the ORVIS Fly-Fishing Guide, with casting tips and detailed knot tying videos. The apps can be viewed on any iPhone, Google Droid, iPod Touch, or iPad. Makes for a nice Christmas gift.