Tool for Calculating Brewhouse Efficiency from User Inputs

In a very old thread I stumbled across:
http://www.beersmith.com/forum/index.php/topic,2898.0.html

The subject of deriving Brewhouse Efficiency from a user's mash efficiency and equipment profile came up, with this response:

BeerSmith said:

Hi,
  Actually the feature to calculate actual efficiency is already in the program.  Click on the "Brewhouse efficiency" button in any open recipe and a small calculator will be displayed to take your actual measurements and calculate the efficiency.

Brad

Click to expand...

Obviously, this refers to the old version of BeerSmith. I think it's a wonderfully timeless tool for brewers and would love to see it reintroduced.