Sparrow, the iOS and Mac email client was bought and killed by Google recently. Announced today: http://9to5mac.com/2012/07/20/google-acquires-sparrow-the-star-third-party-ios-and-mac-email-client/

It was the only half-decent alternative to the built-in Mail app for iOS.

Google has enough cash that I'm surprised they're not making bigger moves to snap up more good iOS apps.