Google provided a small update to the iOS Gmail application today that makes it work better with other Google-developed applications.
Specifically, Gmail users who click Chrome, Google Maps, and YouTube links within Gmail will be taken directly to those on-board applications rather than the mobile web. Users can also choose to turn this feature on or off to suit their preferences. The new Gmail app also allows users to sign out of one Gmail account at a time rather than all accounts at once (Gmail for iOS supports up to five individual email accounts).
Gmail for iOS is a free download from iTunes.