Warlords Classic - official port from Mac/PC/Amiga (universal, was $4.99)
If you're into old school strategy games, grab this now! It's still free — but probably not for long. It's less than 9MB, so you can download it (and play) on-the-go. I don't think I'll spend much time with this one, so let me know what you think!
(I never played the original!) I think I'd rather play Baldur's Gate: Enhanced Edition, however.