FYI the iphone app,AccuTerra,has been updated.Some people tried the app,ATTrail,and didn't like it.AccuTerra does work using the iphone's GPS feature.Tried yesterday on Squibb crk trail.The app is in 2 parts,AT north and AT south $1.99 each.The resolution is much greater and even pinpoints things such as shelters and most trails near the AT and all paved roads.While some features are shown w/o names the main thing I like is that you can use it to plot your movement via GPS thus giving you your location on the AT as you move along.It isn't perfect but if you have an iphone spending 2 bucks basically turns your phone into a GPS device.