I never, ever saw an app on my Amiga that used the help button. ... I'll take my Model M
DOPUS classic: Help key toggles help mode that shows function of GUI elements when clicked. Hard to believe you haven't seen this app.
FinalCalc: Help key opens AmigaGuide help system.
And this just from about 13 seconds of testing, there are many more.
A keyboard that does not have too much over the cursor keys and is -both- an IBM clone and Amiga keyboard is the Nothgate:
http://www.amiga-hardware.com/download_photos/omnikeyultra_big.jpgI have Model M's and I like the Northgate better! (Similiar switch mechanism, but the Northgate has a more rigid steel base)