Might it be the free version and not the paid-for one?
I’ve just figured out that the one I downloaded from www.remarpro.com is called:
‘Calculated Fields Form’ (and doesn’t appear where I expect it to)
while the pro version I purchased is similarly called ‘Calculated Fields Form’.
I figured it out because of slightly different links under the plug-in title.
Maybe you guys might consider re-naming the ‘pro’ version ‘Calculated Fields Form PRO’?
Just a thought.