Which Bluetooth Module Should I Purchase - Beginner

I have a project that reads analog values and displays them on an LCD. I would like to also be able to add bluetooth to my arduino and display it somehow on my iphone, the same way it does on MY LCD. I am having difficulty finding a bluethooth module to choose for this and would really appreciate an expert opinion on one to buy. Also, would i have to develop my own app just to do a printout on my phone over bluetooth?

Thanks

It would be easier if you used an Android smartphone.

Since you are wanting to use an iPhone, you might want to look at http://redbearlab.com/bleshield/

Any BLE (Bluetooth 4) module will do. The HM-10 can be had for about $7, only a dollar or so more than an HC-05. I use the Tinysine version.

As iee488 says, you would be better off using an Android, but I don’t think you would need to write your own app. There is sure to be a simple bluetooth terminal available by now.