The Gmail app finally makes an appearance for the iOS products - namely the iPhone, iPad, and iPod touch yesterday. The user interface is reminiscent of a combination of both the Gmail mobile web app and iOS features.
However, there seem to be a slight problem as noted by Google after its launch. The app has since been removed.
Gmail Blog - Earlier today we launched a new Gmail app for iOS. Unfortunately, it contained a bug which broke notifications and caused users to see an error message when first opening the app. We’ve removed the app while we correct the problem, and we’re working to bring you a new version soon. Everyone who’s already installed the app can continue to use it.
Source: Gmail Blog