If you're looking for a free place to spend the night in your RV try a WalMart parking lot. This free app for iPhone and Droid shows you which WalMart's in your area let you spend the night. It also lists which amenities are nearby.
A good camping trip requires great food. The Coleman Camping Cookbook is a great free app. It features a meal planner, detailed menus and pictures for cooking everything you can possibly imagine.
One other cool app from Coleman: The Creepy Campfire Tales iPhone book. Gather the kids around the fire and scare the bejeebers out of them. This one has a collection of spooky stories, complete with sound effects.