Google is releasing a design update to Gmail for iOS today that tweaks the apps for iOS 7 and introduces new viewing modes on the iPad. While the iPhone version of Gmail remains largely unchanged aside from some bigger fonts and a matching status bar, the iPad version now includes a left-hand navigation bar when in landscape mode that allows for easy access to the inbox tabs that Google introduced in May. In portrait mode, messages will now take up the entire display, rather than just a portion of it, as will the new message composition window.
Update: Though this article originally stated that background refresh hadn't been added into the update, today's Gmail release does now show up in iOS 7's settings as an app that takes advantage of the new feature. Google doesn't detail the addition in its update notes, but it appears that Gmail is finally supporting one of iOS 7's biggest features.