The app I am writing is using Xcode 7. It will display 6-12 temperatures readings hopfully, using your hardware. I understan I need several things like a Arduino board, Bluetooh board etc. My question is what Arduino board do I need or in fact what would you recommend I buy in all hardware for this project. Yes I am new but not afraid 
. Just need some guidance on the required hardware as I would like to buy it all in one shot.
Regards,
I have no idea what Xcode 7 is.
Most people start with an Arduino Uno and go through the examples in the software.
Here is a cheap temperature sensor that is easy to use. TMP36 - Analog Temperature sensor [TMP36] : ID 165 : $2.75 : Adafruit Industries, Unique & fun DIY electronics and kits.
I've never used Bluetooth, so I have no suggestions for that.
BeginnerCoder:
Bluetooh board
To what sort of device will the Bluetooth be communicating? I think HC-05 modules work great with Android devices but I don't know what to recommend for iPhones.
I also have no idea what Xcode 7 is.
BeginnerCoder:
The Aduino will be used to accept thermocouples and translate that information via Bluetooth which the iPhone app will display.
Do you have the thermocouple stuff already? You need special chips to read thermocouples.
I haven't used Bluetooth with an iPhone but I think Adafruit has iPhone friendly Bluetooth modules. They sell most (if not all) of the other stuff you'll need.