That app few years was 49.99 lolI have many of the Apps mentioned but Navionics is by far the best overall app I have used or seen. It's the best $9.99 you'll ever spend.
GPS Kit app will cache Google or Bing Satellite Map areas for use when you are not in cell phone covered areas. Also works on iPad with GPS Kit HD, but the iPad is too big to carry while hunting or velcro to the console of a flats boat.Those are some really neat apps. I'm definitely going to add some of those.
On the subject of google earth, is there anyway the maps can be cached in the event you out of cell phone range and still be used?