If you have an iPhone, iPod, or iPAD with iOS 5 and earlier, you can gift an app from your iDevice. However, with iOS 6, the app gifting function is not available on the device at this time. If you want to gift an app, you must use the iTunes Store on a Mac or PC. I will explain how to gift an app in both ways.
How to gift apps in iTunes on a computer (Mac or PC):
1. In iTunes, click iTunes Store in the Source list on the left panel.
2. Scroll down to the App section.
3. Find the app that you want to give to someone. You can use the search function on the top-right corner.
4. Once the app you are looking for shows up on the screen, click the arrow to the right of the Buy button; in the resulting menu, choose the Gift This App.
5. Once you’ve clicked Gift, you’ll either be asked to sign in with your account name and password, or you’ll see a “Give a Gift” page. It doesn’t matter which screen you get first, you will get both.
6. You have the option to Send the gift via email, or if you want a hard copy to put in a holiday card, you can choose Print gift myself.
7. Once you’ve successfully signed in and completed the gift form, you’ll be brought to a page to review your purchase and confirm it.
Note: Gifts can only be redeemed in the store country from which the gift was bought. If you bought the gift from US Store, your friend can’t redeem it from the UK store.
How to gift apps on iPAD:
If you still have iOS 5 or earlier, you can gift apps from your iPAD. All you have to do is to go to App Store, open the app you want to gift to someone. On the top-right corner, tap on “Gift This App”, then follow instructions.
How to gift apps on iPhone:
Again, if you did not update to iOS 6, you can gift apps from your iPhone. It is a little different from iPAD. Open the app you want to gift within the App store, then scroll all the way down. You will see “Gift This App”. Tap on that, and follow instructions.
Hope these are helpful.