I actually use these sites (mostly Yummly, but I always try new ones), and I have a comment that applies to all of them. It has to do with the variability of the underlying data.

Do I have "parmesan" or "parmesan cheese" or "parmegiano reggiano" or "parmegiano-reggiano"? Also, there is an implied hierarchy to some ingredients. For example, if I have fresh lemons, then I have "lemon juice" and "lemon zest" and "lemon peel".

I don't really know how this site or any others like it handle those types of things. Maybe its fixed behind the scenes, but a visual indicator would be great.