With over 425,000 applications in existence for the iPhone and iPod Touch, many new owners of the Apple iPad will undoubtedly already possess a library of apps that they accumulated for use on the iPhone. Fortunately, you can sync your iPhone apps to the iPad using iTunes on your computer.
Open iTunes on your computer. If you own an iPhone, chances are you already have an active iTunes account. If you don't have iTunes, you can download the latest version free at the Apple website.
Connect the iPhone to your computer using the USB connector cable that came with the device. ITunes detects that the iPhone has been connected. The iPhone name appears under "Devices" in the left navigation column. Click on the name to open the syncing options and then click the sync button in the lower right corner. This backs up all your apps to iTunes. When the sync completes, detach the mobile device.
Connect the iPad to your computer using the USB connector cable that came with the device. The iPad's name shows up under "Devices." Click it and select the "Apps" tab at the top of the main iTunes screen. Uncheck any applications that you do not wish to sync to your iPad. Choose the items you wish to sync and click "Apply" in the lower right corner. Your iPhone apps transfer to the iPad.