Well, software that "assesses" ones grammar and readability may be useful,
but here's what _I_ need  -- BIG LETTERS and BRIGHTLY LIT tags/signage.
 
I have found many displays identified with text too small to read
comfortably, too low for a person 6'5", and too darkly lit to see well,
especially when the display/diorama is well-lit and forces your eyes into
a dance of accommodation between the display and the signage.
 
Older folk (the patrons with disposable income? .....) need to see those
signs. If they can, only then can they get concerned about what the signs
say  ;>)
Peter