I don't use any ipad apps, but I do my iphone instead.
I have both weber apps and I think I got the 2 one on sale or free one day.
For gas grilling, the blue rhino app will give an estimate on tank levels and has a log
I did get the igrill mini but with it had another probe.
Example, 1 probe in the pig,and the other for the overall temperature. That way I can do some work around the house, and know when the food is done or when I need to add charcoal.
I was looking yesterday for a good app to log stuff, I downloaded one and it was junk.