UPDATE: oUkTuRkEyIII has found an even better offer @ Gamesrepublic using the code "REGISTER-10-OFF" (only working for new customers). Final price = £4.72
You get "This War of Mine - The Little Ones" for ~£5.34 @ MacGamesStore, using the 5% code "macgames5off".
This War of Mine: The Little Ones explores the hardships of wartime survival as seen from an entirely new perspective―that of a child. This DLC puts you in charge of a group of adults and children stuck in a besieged city, struggling with basic necessities. TWoM: The Little Ones focuses not only on the reality of enduring war, but also on how even in times of conflict, kids are still kids: they laugh, cry, play, and see the world differently. In addition to thinking about survival, you'll have to summon your inner child to understand how to protect the little ones. Their youth, and their future, are in your hands.