For keeping track of your grocery list, and are both excellent apps that can sync across all of your iOS devices. (The latter Shopping List, however, is not optimized for the iPad's screen.) I tend to remember when I need when I'm in the kitchen and realize it's not there, so entering your grocery list onto your iPad and opening it back up on your iPad while in the store is really useful.

Of course, just because you turn your iPad into a dedicated kitchen tablet doesn't mean you can't use it elsewhere. Most of the stands and mounts mentioned above make it easy to attach and remove your iPad. But using your old iPad as your go-to tool to access all of your favorite recipes, cooking videos, and more right in the kitchen will certainly give the tablet a new and useful life.