Questions

Text, answered

Does it work on a scan?: No. A scan has no text in it, only an image of text.
What happens to tables?: They come out as rows of words. The grid is gone.
Two-column pages?: Usually fine, occasionally interleaved where the reading order was ambiguous.
Is the file uploaded?: No. This one runs in your browser.
What needs a subscription?: Downloading the text file.
Is this the official site?: No — the team behind PDFora publishes it.