Search-as-you-type would indeed be good for prefix data, but the search box itself checks quite a bit -- one-word searches are regularly in the 1,000-card range. I'll look into it, though; I agree that it would improve things.

My UI is terrible, I know. "Leftify" is a great term, btw. Do you think it's visible enough from the header, or should I move it down?

As for "known set of data," the query language is a full, SQL-like language (including compiler to SQL). This is another issue with the search-as-you-type, but compiling an 80-character (ish) search and getting a few results back should be quick and easy, so I'll see what I can do.

Also, did you notice the sorting option, or was it too hidden?