Grill Guide This is a simple app that tells you how to grill all different kind of meat, at what temps and for how long. It's a great way to start planning your meal, and in my experience the times and temps are accurate.
Grill-It! For a buck you can get the same features as Grill Guide, but with the addition of great photos and recipes.
iCooking Barbecue Use this app to hunt up some really unique grill recipes (what did I tell you about ditching burgers and brats?), and try the shopping list feature to make sure you don't miss an ingredient while you're at the store.
BBQ Timer It's basically a glorified stopwatch, but don't forget to set your timer for a perfectly grilled meal. We all know you're going to wander off for a cold beer at some point. Don't sacrifice your steak.