'Three wire calculator' maker here... Thanks for the plug. YES! the program is free, and i have updated the page to reflect that. The program has saved me tons of time from not using pencil and paper. The only bug i'm aware of is the formula's do not display correctly at first start. Sadly, this post is the FIRST instance of anyone referencing or commenting on the program. even though the calculator gets a steady stream of users daily. I would love to port to android/iOS but i am not that capable. That is why the swf is available for download as well.
without purchasing the new flash builder (or similar from adobe), i have only found 'NO' for porting flash/actionscript to almost anything else.
Sorry to rant.
tl;dr
Yes it is free, says the guy who made it.