Additional third party integration with Gmail has been possible (you only have to look at all the contact import features from sites like Facebook), but these have either been clunky manual procedures that involve exporting contacts to a CVS file, or they require you to supply your email password. Neither option is all that attractive. Now there is an alternative. Google have recently added the ability to access the IMAP/SMTP features of particular Gmail account using OAuth.
DE-DE Group’s Birdseye Mail might be the first email client built purely for a tablet environment. Now, the Birdseye Mail API allows developers to integrate Birdseye Mail functionality with third party applications. App developers can take advantage of tablet-specific functionality and add rich email functionality to new and existing apps.