All in-app purchases for iOS only have to be pur­chased once and then they will be avail­able from all your other iOS devices run­ning our app. After making an in-app purchase on one device you will then be able to enable the pack on your other devices by going to the “Set­tings” —> “In-App Pur­chases”  (soon to be renamed “Upgrade Advisor”) and tap­ping on “Restore All Pur­chases” at the top of the screen. You must be using the same iTunes account on all your iOS devices.

The iOS in-app purchases are not available on the Mac and vice versa because Apple manages them as completely separate stores. You will have to separately purchase them.