As you probably know the brandnew iOS devices like the iPad Air enable you to download the iWork and iLife apps for free. What I didn’t know is that once you downloaded them to your new device, they will also be available for free on your older devices.
In my case I bought an iPad Air and also got the apps for free on my older iPhone 5. It makes kinda sense, since the download is tied to your Apple ID, but I still didn’t think about that until I noticed them downloading on my iPhone. In my case Automatic Downlods were enabled. So if you have this unchecked you just need to download the apps manually. The will show the Cloud icon instead of a price.
No great hint, but maybe someone else didn’t think about that, too.
Source: Mac OSX Hints