Apple has added the Gmail Archive feature to the native Mail.app in iPhone OS 4.0. This feature lets you archive your email for later reading.
To archive a Gmail message, simply swipe on the message just like you delete a message and archive button will appear. Have a look at the screenshot below:
iPhone OS 4.0 has brought many improvements to the Mail app including unified mailbox, Threaded message, fast inbox switching, multiple exchange accounts, and open attachment with apps. Now the most requested feature by Gmail users has also made its way to Mail.app, thanks to Apple. You can checkout complete list of features in iPhone firmware 4.0 here.
Update 1: iPhone firmware 4.0 beta 3 is out noe:
Update 2: Orientation Lock and iPod Widget found in iPhone 4 beta 3
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