When Carter Dotson reviewed Mailbox a little while back, he loved it. And rightly so; it's an app that makes email a cinch to deal with.
The new and improved Mailbox 1.6.0 is even better, having been redesigned for iOS 7. It's faster, smoother, and generally a better experience overall. The interface has been redesigned and a lot of the visual clutter has been axed. This resulted in a cleaner-looking UI, but also one that's a bit more functional thanks to the developers taking the time to revamp it a bit more thoroughly.
So now it's easier than ever to get that coveted Inbox Zero!