Google has updated their native Gmail app to version 2.4. New features include what they're calling "enhanced email attachments" which appears to translate into larger thumbnails and full screen previews. Also on board is better integration with two other Google apps - Google Drive and Google+. Links to either now go directly to the appropriate app instead of the web. Google does point out that feature can be disabled via the in-app settings, for those who find the integration to close for comfort.
You can grab the Gmail app, or the update, via the App Store now.