I bought Hero Academy on steam for PC a while ago so I could get the Team Fortress, now I'm having trouble figuring out how to get the game on my Mac.
Download Steam on Mac and you're all set. No additional purchase required.
I have steam on my Mac
Did you attempt to "Play" while on Steam? Once you do, it should ask you if you want to create a new account or use an existing one. Put your credentials in for your existing one (that you play via iOS) and it'll link the two account and resolve which teams are yours.
Hope this helps.
Equal parts cur, mud, and gin.
Never shaken, but often stirred.
Serving suggestion: Usually taken with a pinch of salt.
Last time I checked, Hero Academy was not available for Mac. Looks like it's PC only for the time being (via Steam), unless something changed recently.
Edit: Looks like it is supposed to be available for Mac, although it tells me that it's not available for my platform when I log into Steam on my Mac....strange.