Best iphone app I have found yet. Price- free! if you want detailed charts you can purchase entire US detailed blue charts for $30. Best feature to me is that you can view Active Captain within this app-- even without an internet connection! this is an awesome feature for me! charts are great, no active gps though! this is for planning purposes only. not sure how to transfer your routes from the mobile app to a plotter , but it can be done. Weather,etc also available with this app to overlay on the blue charts.

Rodd L