BLUETOOTH Module and Apps

Hello
I am using the HC6 to interface to a netduino Plus 2. I need to setup my Bluetooth device to just connect with a phone coming to talk with it with a phone app on android. I am using android studio. Does anyone have an android studio sample app to talk to a Bluetooth device connected to the netduino? I also am tying to have the Bluetooth device connected to the netduino be in a mode to just receive request from an android app. Can anyone help me with this? I always have pairing problems. Does this hardware HAVE to pair? What I would really like is for the netduino to respond to any cell phone running the app. Kind of a promiscuous mode.

Please let me know. I have been out of the game a while.

Thank you

I've used both HC5 and HC6, without problems.  The default pairing code is (on mine anyway) 1234.  Once paired, should automatically connect when in range.  Scanning for it on your target phone or tablet should pick up the mac address of the HC.  Very simple to connect, VDD, GND, HC TX goes to Serial RX on Netduino, HC RX goes to Serial TX on Netduino.  I've run mine on both 3.3v and 5v.