preview panel in Gmail - read mails the way you read in a mail client

Gmail preview panel

Gmail was always looking to add up some to their gmail app and they were coming up with some cool and new features since the launch of the Google social network Google Plus. The feature will not be available until you enable it for use from Google labs.
After enabling the feature a preview panel will be added and you can see the preview of the mails and reply to them with ease and more effectively, the user interface after adding the panel looks similar to gmail for tablet devices. So if you read your g-mails online it is a very effective addon to have to boost your work. You can enable the feature from google labs here.