The official GMail app for iOS today got an update of features that really should have been there since it launched. As described in the official GMail Blog, the big addition is Notification Center support. That means banners, alerts, and lock screen notifications.
Also available now in the GMail iOS app is the ability to send emails from an alternate email address, if you have it set up on your GMail account already, and permanent login so your account doesn’t just time out on its own.
Unfortunately, the GMail app is still pretty poor in that it’s mostly just a webapp, without the offline browsing of messages that so many hoped it would have. Nonetheless, every improvement helps.