Q: I have an iPhone 4 and just purchased an iPad 2. How can I have the same apps on both the iPhone and iPad without having to purchase the apps again? Where can I find out how to sync both units but be able to keep them separate from one another.
A: In terms of syncing both your iPhone 4 and your iPad 2, this is really just as simple as plugging the iPad 2 into the same iTunes library. iTunes treats each iPod, iPhone and iPad as a separate device and maintains distinct settings for them automatically, so you can choose how you want to manage the content for each device individually and can even connect and sync them to your computer at the same time.
The easiest way to use your apps on both devices is to ensure that they are in your iTunes library and sync them from iTunes onto the iPad 2 in the same way as you would for your iPhone. You can install the same applications on all of your iOS devices that are synced with the same iTunes library. Note that you can also go to the App Store on your iPad 2 and reinstall the apps from there—the App Store recognizes that you have already bought the apps and won’t charge you for them again when you re-download them.
If you don’t already have your applications in your iTunes library, you can easily transfer them back from your iPhone simply by ensuring your computer is authorized for the same iTunes Store account that was used to purchase the apps and then syncing your iPhone with your computer.
During an automatic sync, iTunes will transfer back any apps and media content it finds on your device that your computer is authorized for. You can authorize your computer for your iTunes Store account by going to the Store menu in iTunes and choosing the Authorize Computer option.
Note that while all iPhone apps will run on the iPad in a screen-doubled backward compatibility mode, you’ll get the best experience if you use native iPad applications on your iPad 2. Some iPhone apps are “universal” meaning they include native support for both the iPhone and iPad in the same application, while others may offer a separate iPad version of the app.