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:
Tap Mail, Contacts, Calendars. Then tap Add Account.
If you entered your account information properly, you'll see that your account was verified.
Select the apps you wish to sync, then click Save.
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.
In the Sign-in & Security section, select Connected apps & sites.
Scroll down to the Allow less secure apps section and change the setting to On. You should now be able to connect your account to an email client.