If you've registered your drone to get an FAA number, the website also recommends the app "B4UFLY" which is by the FAA and will not only tell you how close to an airport you are but allows you to log 1) how high will you fly. 2) how far will you fly. 3) how long will you fly there.
I'm assuming it's to log where you are for any flight patterns associated with your area, the app also has a map of the area showing planes and helicopters in your area, a planner and more... if this could justify your flying in an airspace that is a flight path approved by a helicopter or small plane at the same time.... but then again it is FAA and might be used against you.... worth downloading and checking it out.
Ramrod