This tutorial demonstrates how to configure an iOS device for CU Boulder's Gmail.
Screenshots are from an iPad, but steps apply to all iOS devices.
You may need to enable IMAP for your account prior to configuration of your email client (https://mail.google.com). To do this:
Your account should now be configured properly and you should see your account listed in your Mail app.
Some users may need to change their app security settings when using non-google and android email programs. While signed into your Gmail account in a browser, open the Google Apps menu, then select My Account.
*Note: You should try to connect your account without changing these settings and change only if the previous steps don't work.