Today I brought my Phantom over to my cousins home in Pembroke Pines, FL and the area we were going to fly is within the 5 mile control range of North Perry Airport (I was about 4.8 miles from the airport),  before I took off I attempted to contact the tower from the number in the Hover app (it is the correct number) unfortunately I got an answering machine, so I left a message and told them my location in relation to the airport and that I would be flying up to 400 feet, after flying I called them again, this time someone answered and I told her I was calling in to let them know I had completed my flying for the day, she asked me to hold on, a controller then picked up the phone and thanked me for calling them and that he had received the message I had initially left and that info was given to the tower.  He was very polite and thanked me for my 2 notifications. They appreciate that we are being responsible for our flights. He even told me of a situation they recently had as there is a college out the perimeter of the airport and some students started flying a multi-copter  without informing them before their flight, and they are right within hundreds of feet from the runways and flight paths, hey quickly sent someone out to ground them. Apparently they were not aware of the guidlines or had the common sense to figure out what they were doing was wrong.

That's good that they appreciated your call. Where I live there is an website controlled by  the CAA, that you can submit your flight plans too, and it sends it to the appropriate control tower (where supposed to wait for it to be approved/denied). I'm glad it's an easy process for you, inside the 4km radius around an aerodrome here is damn near impossible, requires a physical barrier that can stop your UAV from flying towards the aerodrome, and/or a trained pilot as an observer.