As others mentioned, Campendium, and I also like iOverlander, but it depends on the type of camping. Campendium is great for regular RV sites and even for boondocking spots. If you’re a memebr of a club, like KOA, Harvest Hosts, etc., you’ll want to use their apps. Usually, you’ll find campgrounds on one app that you won’t on another, so I typically check a few apps when searching.
