I don't think the airmap app is recognized by the FAA, but I could be wrong. In fact, I read something about that earlier but it didn't go into much detail. You don't need a license to fly it as a hobby, but if you intend to make any money you'll need a license. As far as that airport part is concerned, there are all kinds of restrictions, so I can't answer that. There are certain protocols that must be followed when flying within a certain distance of an airport, and each one can be different especially if there are special temporary restrictions in place.