To get the Google Mobile App on your iPhone or iPod touch device, make sure your device has the latest version 2.0 firmware or above and follow these general steps:
1. Select the App Store icon on your device's home screen.
2. Search the App Store for the Google Mobile App.
3. Tap Free > Install and sign into your iTunes account if necessary.
A Google icon will appear on your homescreen with a status bar for the download and installation.
You can also install the App by searching for Google Mobile App from the App Store in iTunes, downloading it, and syncing applications between iTunes and your device.