I appreciate all the replies so far. I am going to download the above mentioned apps and try them out. Something I wasn't aware of was that maps would store on an iphone. I have stored google maps and USGS maps on my boat's Nexus 7 tablet for plotting uncharted river navigation. The ability to store enough maps for a few days is a huge plus for me.

As to Marcus's concerns about cellular coverage, I have verizon and I am aware there are many areas of the country without coverage. I have no plans on leaving my maps at home
My touring these days range from overnighters to two week trips.