I just pushed out a small change that enables ViewText to work with YouTube.  Only the title, video, and description are left, everything else is removed.  The preview is resized for mobiles to fit in either portrait or landscape mode.  Have a look at an example.

I'm also thinking about including the Coleman-Liau index for pages, or a least a way to retrieve it, but the algorithm is somewhat in flux.  Odd for something defined in 1975 to be so uncertain today.  I've found several definitions of the algorithm, all slightly different, but similar enough that any can be used.  This discussion on Wikipedia gives some insight.