LocPDF is a visual search engine for PDF’s on the Web. In other words, you see thumbnail sketches of the PDF’s that are in your search results.
I really don’t know how big of a deal it is, or how different the search results are than from typical search engines, but I know when I typed in “parent engagement” I found some resources I hadn’t seen before. It was neat being able to see the images first.
I don’t think it’s particularly useful for English Language Learners, but I think it’ll be useful for teacher research.