Better than the iGrill is the Tappecue. Costs a bit more, but it is a better unit. I've tried both and much prefer the Tappecue unit. They came out with a new unit a few months ago which is the one that I waited to purchase. It uses wifi for connectivity instead of bluetooth. That means that I now have the ability to monitor what is going on inside my smoker when I'm at work or out running errands. Setup is easy and the accuracy seems better than the iGrill. Now, don't get me wrong, I'm not saying the iGrill is bad. It is still a fine piece of equipment. I just prefer the other because it gives me the freedom to have my phone more than 30' (bluetooth distance) away from the thermometer to see what is going on.
I'm not posting the link to their site (though logic will get you there) as I'm not paid to promote their product.