Sending data from RN-171 in adhoc mode
I noticed that port 80 was open


On an RN-171? This module supports HTTP client mode only and has no HTTP server, unless we talk about custom firmware.


  somehow sends a message to the microprocessor


Sounds like you really need to read the (WiFly) manual again. The RN-171 has a UART interface, and you can use it to talk through the WLAN module from our microcontroller to your iPhone, in both ways. In short, you open a tcp port on your phone and use it like an oldschool serial port that is connected to your MCU.