Sparrow, the popular email client for iPhone, was acquired by Google over the summer, and it was announced the acquisition would mean no more feature updates for the app. However, that doesn't mean the Sparrow team would skip full iOS 6 and iPhone 5 support, so they ended up pushing out an update, but to everyone's surprise, it was rejected by Apple.
Sparrow developer Dinh Viet Hoa announced on Twitter that the Sparrow app update for iOS 6 and the iPhone 5 was rejected by Apple, and explained why later on in a reply. Apple's rejection had something to do with the app's Rich Text format. The developer was told that if they didn't update the app with the corrections, it would be removed from the iTunes App Store.
Rich Text editing in email is a feature that Apple added in iOS 6, which means that the Sparrow team will have to release an update for the email client that will be for iOS 6 only in order to take advantage of Rich Text. iOS 5 users will still be able to use Sparrow, but they won't be able to update to this latest version.
However, Rich Text support is actually built into Apple’s own Mail client in iOS 5, so we're not sure why Apple has a problem with Sparrow's Rich Text formatting in this latest update, which would've been compatible with iOS 5. Then again, the update is meant for iPhone 5 users who are already running iOS 6 anyway, so it shouldn't be a huge problem for a majority of Sparrow users.
[via The Next Web]