Seems this "b4ufly" app thing is a beta test program.....so far. You can read thru the FAQs here:

http://www.faa.gov/uas/b4ufly/media/UAS_B4UFLY_QandA.pdf

I don't see a way to download it to conventional desktop computers. If I'm correct, that's too bad. I'd suggest that not everyone keeps their phone on their hip 24 hrs/day. I don't. But, I like to do map research & planning via computer. You can enlarge screens & actually see something without pretending. Many drone operators are not 35 yrs old any more. It's been 32 yrs since I was able to see that well.

Anyway, do they give the telephone # on "who to contact" on those "contact the airport" deals? I can just about guarantee you if you wake up on a Sunday & find it's a beautiful day with less than 10 mph surface wind & you decide it would be a great day to take photos of your corn field located 4.5 mis S of the geographical center (!!!!!!) of XXXX airport, which is a municipal, single runway, uncontrolled (meaning no ATC tower) airport, and a limited hour FBO (the guy that pumps the gas....but usually doesn't make political or financial decisions).....you're not going to get anyone to answer. Often the airport mgr may be a non-full time employee, or sometimes it's a person appointed by the local airport board, or sometimes it is the guy that runs the charter service on the airport. But anyway, call on a Sunday @ 0900 hrs & you'll get nothing. The guy driving the fuel truck will probably say, "hey....I don't care, but I'm not the decision maker....". I'd guess that 97% of the airports in the USA are of this type. If you're thinking of flying near Indianapolis Intl, that's different. Good luck.

Then what? The legal FAA answer will be if you got no response from the airport in question...that meant you got no permission granted. This "contact the airport..." thing is a joke. I base this on 25+ yrs experience of being based on an airport as a commercial entity.

Also, as I understand the FAQs, you'll never be given a "green signal". Is that correct?