Telltale Games Forums - Buying a digital download for someone else?

There isn't currently an easy way to gift a game (there used to be a box to check at checkout when the game purchased was a gift), but here's what Telltale's MattP suggested in another thread (replace the word "sister" by "brother" and you're all set ;)).

Quote:

Originally Posted by MattP (Post 746189)

If you provide your sister's email address, I can transfer the game to her account after you buy it. If you've already registered her account, then you can provide her with the details. If you have not, the process is slightly more complicated. Please send me a PM with your details (order number, email address, name) and her email address, and what route you'd prefer to go and I can take care of it.

As for the Mac/Windows part of your question, buying the game from the Telltale Store will get you the Mac AND Windows versions of the game, no matter what kind of a computer you use to make the purchase.
Hope this helps!