I've got the Igrill2. It works fantastically for me. The app is kind of annoying in that as soon as you shut off the main unit you don't seem to be able to access your data from the cook. Maybe there is a way to do it that I don't know. The problem with IGrill2 is probably the Bluetooth range. For me it happens to work great. Other's have had issues. ICelsius uses WIFI and has much better range.
So far I love the Igrill2. It looks awesome and that doesn't hurt.