When it was released for the iPhone and the iPad last year, Mailbox took the iOS world by storm with its unique and streamlined approach to e-mail management on the go. Users with overflowing inboxes striving for “Inbox Zero” nirvana came to appreciate the ability to quickly and easily file messages away or defer them for later with straightforward swipe and tap gestures. The missing piece for many power users, however, was access to the…