Google just published a new update to Gmail for iOS. Gmail 4.0 has arrived in your App Store updates, bringing with it several new features designed to make life easier for those who use the app to handle multiple Gmail accounts... or even just a single Gmail account.
First, you'll find that notifications from Gmail let you either reply or archive a message with a single tap. That's a wonderful way to delete unimportant messages without even having to open the Gmail app.
Next, Google has added a share extension that allows Gmail users to send attachments from any app that supports the iOS 8 share sheet. You'll need to activate the extension by tapping "More" on the list of app icons that appears on the share sheet, then sliding the switch next to Gmail to the on position.
Finally, there's also a new attachment viewer for Gmail 4.0 that allows users to open email attachments in any compatible app. All in all, it's a solid update for Gmail users.