I use that applet as a pitch speed calculator... nothing else... I can do it by hand, but this is faster.

I put in numbers once for an APC 16x8 and a Master Airscrew 16x8 at 9000 rpm... the program always predicts higher thrust from the an APC because they are more efficient, yet in reality the Master Airscrew gives a lot more thrust than the APC, probably because of the difference in blade width and tip pitch...
A Master Airscrew puts a much heavier load on an engine compared to an APC of the same size... (in reality, not in Thrust HP)

A program this simple to compute something this complicated and complex is crap IMO...

And I don't understand why engine manufactures with supposedly good reputations do hp and thrust claims, backed up by this program...